A287307 - OEIS

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A287307

Primes that can be generated by the concatenation in base 6, in descending order, of two consecutive integers read in base 10.

13, 41, 443, 739, 887, 1109, 9547, 11717, 14321, 16057, 17359, 18661, 19963, 22133, 22567, 23869, 25171, 28643, 29077, 31247, 32983, 33851, 35153, 40361, 43399, 44267, 44701, 45569, 287933, 290527, 303497, 306091, 311279, 319061, 337219, 345001, 389099, 391693

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..38.

EXAMPLE

1 and 2 in base 6 are 1 and 2 and concat(2,1) = 21 in base 10 is 13;

5 and 6 in base 6 are 5 and 10 and concat(10,5) = 105 in base 10 is 41.

MAPLE

with(numtheory): P:= proc(q, h) local a, b, c, d, k, n; a:=convert(q+1, base, h); b:=convert(q, base, h); c:=[op(a), op(b)]; d:=0; for k from nops(c) by -1 to 1 do d:=h*d+c[k]; od; if isprime(d) then d; fi; end: seq(P(i, 6), i=0..1000);

MATHEMATICA

With[{b = 6}, Select[Map[FromDigits[Flatten@ IntegerDigits[#, b], b] &, Reverse /@ Partition[Range[0, 302], 2, 1]], PrimeQ]] (* Michael De Vlieger, May 23 2017 *)

CROSSREFS

Cf. A000040, A052089.

Sequence in context: A146995 A102130 A080186 * A332255 A201121 A116153

Adjacent sequences: A287304 A287305 A287306 * A287308 A287309 A287310

KEYWORD

nonn,base,easy

AUTHOR

Paolo P. Lava, May 23 2017

STATUS

approved