A341437 Numbers k such that k divides Sum_{j=0..k} j^(k-j).

1, 2, 6, 7, 9, 42, 46, 431, 1806, 2506, 11318, 16965, 25426, 33146, 33361, 37053, 49365, 99221, 224506, 359703, 436994

Offset

1,2

Comments

Numbers k such that k divides A026898(k-1).

a(19) > 10^5.

Links

Table of n, a(n) for n=1..21.

Formula

0^6 + 1^5 + 2^4 + 3^3 + 4^2 + 5^1 + 6^0 = 66 = 6 * 11. So 6 is a term.

Mathematica

Do[If[Mod[Sum[PowerMod[k, n - k, n], {k, 0, n}], n] == 0, Print[n]], {n, 1, 3000}] (* Vaclav Kotesovec, Feb 12 2021 *)

Prog

(PARI) isok(n) = sum(k=0, n, Mod(k, n)^(n-k))==0;

Crossrefs

Cf. A026898, A128981, A188775, A341436.

Sequence in context: A047277 A308198 A358579 * A327985 A189465 A109783

Adjacent sequences: A341434 A341435 A341436 * A341438 A341439 A341440

Keyword

nonn,more

Author

Seiichi Manyama, Feb 11 2021

Extensions

a(19) from Vaclav Kotesovec, Feb 14 2021

a(20)-a(21) from Chai Wah Wu, Feb 15 2021

Status

approved