Displaying 1-10 of 10 results found.
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Maximal digit value used when n is written in primorial base (cf. A049345).
+10
54
0, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3
EXAMPLE
For n = 2105, which could be expressed in primorial base for example as "T0021" (where T here stands for the digit value ten), or maybe more elegantly as [10,0,0,2,1] as 2105 = 10* A002110(4) + 2* A002110(1) + 1* A002110(0). The maximum value of these digits is 10, thus a(2105) = 10.
MATHEMATICA
With[{b = MixedRadix[Reverse@ Prime@ Range@ 20]}, Array[Max@ IntegerDigits[#, b] &, 105, 0]] (* Michael De Vlieger, Oct 30 2019 *)
PROG
(PARI) A328114(n) = { my(i=0, m=0, pr=1, nextpr); while((n>0), i=i+1; nextpr = prime(i)*pr; if((n%nextpr), m = max(m, (n%nextpr)/pr); n-=(n%nextpr)); pr=nextpr); (m); };
(PARI) A328114(n) = { my(s=0, p=2); while(n, s = max(s, (n%p)); n = n\p; p = nextprime(1+p)); (s); }; \\ (Faster, no unnecessary construction of primorials) - Antti Karttunen, Oct 29 2019
CROSSREFS
Cf. A002110, A049345, A051903, A061395, A276086, A267263, A276150, A327969, A328316, A328322, A328389, A328390, A328392, A328394, A328398, A328403, A328835.
Cf. A276156 (indices of terms < 2).
1, 1, 1, 1, 1, 3, 2, 2, 2, 1, 2, 3, 4, 3, 2, 5, 2, 2, 4, 2, 5, 4, 5, 10, 6, 6, 8, 6, 5, 9, 1, 2, 3, 2, 2, 4, 2, 2, 3, 1, 3, 3, 5, 4, 3, 5, 7, 4, 4, 8, 3, 3, 4, 9, 9, 8, 7, 11, 4, 8, 3, 3, 4, 4, 3, 4, 2, 2, 3, 7, 10, 10, 5, 4, 6, 3, 8, 9, 7, 5, 10, 10, 10, 8, 5, 5, 8, 6, 9, 7, 4, 4, 6, 9, 4, 7, 8, 5, 3, 5, 7, 4, 7, 7, 11, 9
PROG
(PARI)
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A328114(n) = { my(s=0, p=2); while(n, s = max(s, (n%p)); n = n\p; p = nextprime(1+p)); (s); };
CROSSREFS
Cf. A002110, A051903, A143293, A276086, A276087, A328114, A328322, A328390, A328391, A328392, A328395.
0, 0, 1, 1, 1, 0, 1, 3, 1, 1, 1, 1, 2, 1, 1, 4, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 0, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 3, 1, 1, 1, 1, 1, 2, 2, 7, 2, 2, 2, 3, 3, 3, 3, 3, 3, 2, 2, 4, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2
FORMULA
For all n >= 1, a(n) >= A328114(n)-1. [Because arithmetic derivative will decrease the maximal prime exponent ( A051903) of its argument by at most one]
PROG
(PARI)
A051903(n) = if((1==n), 0, vecmax(factor(n)[, 2]));
A327860(n) = { my(s=0, m=1, p=2, e); while(n, e = (n%p); m *= (p^e); s += (e/p); n = n\p; p = nextprime(1+p)); (s*m); };
CROSSREFS
Cf. A002110, A003415, A051903, A276086, A327860, A327969, A328114, A328388, A328389, A328390, A328392.
0, 1, 1, 2, 1, 3, 1, 1, 1, 1, 1, 4, 2, 2, 4, 6, 1, 3, 2, 2, 4, 5, 6, 7, 3, 7, 10, 7, 6, 9, 1, 1, 2, 2, 3, 5, 2, 4, 2, 1, 3, 4, 3, 5, 2, 6, 9, 4, 3, 10, 3, 6, 8, 2, 8, 5, 7, 7, 5, 10, 2, 2, 3, 4, 2, 6, 4, 2, 6, 9, 3, 4, 4, 5, 6, 9, 6, 7, 5, 7, 9, 5, 11, 10, 4, 3, 5, 11, 16, 7, 4, 3, 5, 2, 5, 6, 5, 7, 4, 6, 8, 10, 5, 9, 12, 11
PROG
(PARI)
A327860(n) = { my(s=0, m=1, p=2, e); while(n, e = (n%p); m *= (p^e); s += (e/p); n = n\p; p = nextprime(1+p)); (s*m); };
A328114(n) = { my(s=0, p=2); while(n, s = max(s, (n%p)); n = n\p; p = nextprime(1+p)); (s); };
Numbers k such that the primorial base representation of their arithmetic derivative does not contain digits larger than 1.
+10
6
0, 1, 2, 3, 5, 7, 9, 10, 11, 13, 14, 15, 16, 17, 19, 23, 28, 29, 30, 31, 37, 41, 43, 45, 47, 53, 58, 59, 61, 62, 67, 71, 73, 74, 79, 83, 87, 89, 97, 101, 103, 107, 108, 109, 112, 113, 127, 131, 136, 137, 139, 149, 151, 155, 157, 161, 163, 167, 173, 179, 181, 189, 191, 193, 197, 198, 199, 203, 209, 210, 211, 212, 217
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
ismaxprimobasedigit_at_most(n, k) = { my(s=0, p=2); while(n, if((n%p)>k, return(0)); n = n\p; p = nextprime(1+p)); (1); };
CROSSREFS
Positions of nonzero terms in A341517.
1, 1, -1, -1, 0, -1, 0, -1, 0, -1, 1, -1, 0, -1, -1, 1, 1, -1, 0, -1, 0, 0, 0, -1, 0, 0, 0, 0, 1, -1, 1, -1, 0, 0, 0, 0, 0, -1, 0, 0, 0, -1, 0, -1, 0, 1, 0, -1, 0, 0, 0, 0, 0, -1, 0, 0, 0, 0, 1, -1, 0, -1, -1, 0, 0, 0, 0, -1, 0, 0, 0, -1, 0, -1, 1, 0, 0, 0, 0, -1, 0, 0, 0, -1, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0, -1, 0, -1, 0, 0
FORMULA
For all n > 1, abs(a(n)) = [ A328390(n)==1], where [ ] is the Iverson bracket.
a(p) = -1 for all primes p.
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
CROSSREFS
Absolute values give the characteristic function sequence for A341518.
Numbers k such that the maximal digit value in primorial base expansion of the arithmetic derivative of k is less than the maximal exponent in the prime factorization of k.
+10
5
8, 9, 16, 24, 28, 32, 40, 45, 48, 81, 96, 108, 112, 120, 125, 128, 136, 160, 184, 189, 192, 198, 208, 212, 225, 236, 244, 250, 256, 270, 288, 296, 352, 361, 459, 507, 625, 640, 768, 800, 832, 864, 896, 928, 960, 972, 1008, 1024, 1056, 1088, 1104, 1120, 1152, 1168, 1184, 1232, 1272, 1280, 1320, 1344, 1350, 1408, 1440
COMMENTS
These seem to be rarer than A351075. All terms are nonsquarefree.
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A051903(n) = if((1==n), 0, vecmax(factor(n)[, 2]));
A328114(n) = { my(s=0, p=2); while(n, s = max(s, (n%p)); n = n\p; p = nextprime(1+p)); (s); };
Difference between {the maximal digit value in primorial base expansion of the arithmetic derivative of n} and {the maximal exponent in the prime factorization of n}.
+10
4
0, 0, 0, 0, 0, 1, 0, -1, -1, 0, 0, 0, 0, 0, 0, -3, 0, 1, 0, 2, 1, 1, 0, -1, 0, 1, 1, -1, 0, 0, 0, -2, 1, 2, 1, 0, 0, 2, 1, -1, 0, 1, 0, 1, -1, 3, 0, -1, 0, 0, 2, 2, 0, 0, 1, 0, 2, 0, 0, 1, 0, 0, 1, 0, 2, 1, 0, 0, 3, 3, 0, 2, 0, 0, 2, 1, 2, 1, 0, 1, -1, 1, 0, 2, 2, 1, 0, 1, 0, 2, 2, 1, 1, 2, 3, -3, 0, 0, 0, 2, 0, 2, 0, 2, 1
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A051903(n) = if((1==n), 0, vecmax(factor(n)[, 2]));
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
Composite numbers k such that the maximal digit value in primorial base expansion of the arithmetic derivative of k is not larger than the maximal exponent in the prime factorization of k.
+10
2
4, 8, 9, 10, 12, 14, 15, 16, 24, 25, 28, 30, 32, 36, 40, 45, 48, 49, 50, 54, 56, 58, 62, 64, 68, 74, 81, 87, 96, 98, 99, 108, 112, 120, 125, 128, 136, 155, 156, 160, 161, 162, 184, 189, 192, 196, 198, 203, 204, 208, 209, 210, 212, 217, 220, 221, 224, 225, 236, 244, 246, 247, 250, 252, 256, 268, 270, 272, 280, 282, 288
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A051903(n) = if((1==n), 0, vecmax(factor(n)[, 2]));
A328114(n) = { my(s=0, p=2); while(n, s = max(s, (n%p)); n = n\p; p = nextprime(1+p)); (s); };
a(n) = 1 if the maximal digit in the primorial base representation of n' is less than the maximal exponent in the prime factorization of n, where n' stands for the arithmetic derivative of n, A003415.
+10
2
0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A051903(n) = if((1==n), 0, vecmax(factor(n)[, 2]));
ismaxprimobasedigit_at_most(n, k) = { my(s=0, p=2); while(n, if((n%p)>k, return(0)); n = n\p; p = nextprime(1+p)); (1); };
CROSSREFS
Characteristic function of A351098.
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