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.

A233193 Numbers k such that k divides 1 + Sum_{j=1..k} prime(j)^11.

Original entry on oeis.org

1, 2, 4, 5, 6, 10, 12, 17, 22, 45, 87, 217, 546, 17806, 41850, 127973, 189586, 435067, 475810, 595932, 3319478, 3737221, 5741156, 7349730, 7473734, 13114674, 26076896, 48515830, 48791555, 419983404, 2217443166, 2617207503, 2894318150, 8776851351, 118596802796
Offset: 1

Views

Author

Robert Price, Dec 05 2013

Keywords

Comments

a(47) > 3*10^13. - Bruce Garner, Jun 05 2021

Examples

			a(5)=6 because 1 plus the sum of the first 6 primes^11 is 2079498398712  which is divisible by 6.
		

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 < 41000000000, s = s + p^11; If[Mod[s, ++k] == 0, AppendTo[lst, k]; Print[{k, p}]]; p = NextPrime@ p] (* derived from A128169 *)
    With[{nn = 5*10^7},Select[Thread[{Accumulate[ Prime[ Range[nn]]^11] + 1, Range[nn]}], Divisible[#[[1]], #[[2]]] &][[All, 2]]] (* The program generates the first 29 terms of the sequence. To generate all 34, change the value of nn to 878*10^7, but the program will take a long time to run. *) (* Harvey P. Dale, Mar 09 2017 *)

Extensions

a(35) from Karl-Heinz Hofmann, Mar 07 2021