A341890 Least k > 1 such that (n^n+k^k)/(n+k) is an integer.

3, 2, 3, 4, 2, 3, 3, 2, 3, 5, 9, 4, 11, 14, 3, 16, 6, 3, 5, 5, 3, 10, 5, 3, 5, 6, 3, 4, 4, 4, 7, 18, 3, 17, 5, 9, 7, 26, 3, 10, 7, 6, 7, 20, 5, 7, 23, 6, 7, 8, 3, 12, 13, 10, 5, 8, 13, 3, 11, 3, 16, 6, 3, 29, 5, 6, 21, 6, 3, 5, 9, 6, 5, 17, 3, 19, 7, 12, 7, 20, 3, 5, 19, 12, 15, 42, 3, 13, 4, 6, 7, 14, 15, 34, 5, 12, 15, 14, 3

Offset: 1

Author

Seiichi Manyama, Jun 04 2021

Keywords

• nonn
• look

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A242801, A242899, A341760, A341844, A341889.

Programs

Mathematica

a[n_] := Module[{k = 2}, While[! Divisible[n^n + k^k, n + k], k++]; k]; Array[a, 100] (* Amiram Eldar, Jun 04 2021 *)

PARI

a(n) = my(k=2); while((n^n+k^k)%(n+k)!=0, k++); k;

Formula

a(n) <= n for all n > 1.