The On-Line Encyclopedia of Integer Sequences (OEIS)

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A358221 revision #11

A358221

Numbers k such that A003415(k) divides A276086(k), where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function.

2, 3, 5, 6, 7, 9, 11, 13, 17, 19, 21, 23, 25, 26, 29, 31, 33, 37, 38, 41, 43, 46, 47, 49, 53, 59, 61, 65, 67, 71, 73, 77, 79, 83, 89, 94, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 141, 146, 149, 151, 157, 161, 163, 167, 173, 179, 181, 185, 191, 193, 197, 199, 201, 206, 207, 209, 211, 221, 223, 227, 229, 233

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..72.

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); };

A358220(n) = if(n<2, 0, !(A276086(n)%A003415(n)));

isA358221(n) = A358220(n);

CROSSREFS