cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A233349 Numbers k such that k divides 1 + Sum_{j=1..k} prime(j)^13.

Original entry on oeis.org

1, 2, 4, 6, 10, 12, 52, 74, 136, 242, 305, 670, 1431, 1706, 1713, 3956, 18331, 22238, 25162, 107332, 162778, 169479, 431228, 459704, 1808681, 1813273, 5954563, 10351930, 27931668, 32490143, 201039164, 311357190, 733854046, 1677164490, 3722808264, 9000784596
Offset: 1

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Author

Robert Price, Dec 07 2013

Keywords

Comments

a(47) > 1.4*10^13. - Bruce Garner, May 05 2021

Examples

			a(5) = 10 because 1 plus the sum of the first 10 primes^13 is 10816960132320284800 which is divisible by 10.
		

Crossrefs

Cf. A085450 (smallest m > 1 such that m divides Sum_{k=1..m} prime(k)^n).

Programs

  • Mathematica
    p = 2; k = 0; s = 1; lst = {}; While[k < 40000000000, s = s + p^13; If[Mod[s, ++k] == 0, AppendTo[lst, k]; Print[{k, p}]]; p = NextPrime@ p] (* derived from A128169 *)