A302089 -id:A302089 - cp's OEIS frontend

11, 29, 167, 279941, 4941263

Offset: 1

Seiichi Manyama, Apr 01 2018

The next term is too large to include.

The next term has 286 digits. - Harvey P. Dale, Oct 24 2021

Primes of form b*k^k + b - 1: A216148 (b=2), A301811 (b=3), A301808 (b=4), A302089 (b=5), this sequence (b=6).

Select[Table[6 n^n + 5, {n, 20}], PrimeQ] (* Harvey P. Dale, Oct 24 2021 *)

a(n) = 6*A302090(n+1)^A302090(n+1) + 5.

3, 5, 9, 183, 561

Offset: 1

Seiichi Manyama, Apr 01 2018

a(6), if it exists, is greater than 5000. - Vaclav Kotesovec, Apr 01 2018

a(6), if it exists, is greater than 20000. - Michael S. Branicky, Sep 02 2024

Numbers k such that b*k^k + b - 1 is prime: A110932 (b=2), A160360 (b=3), A301520 (b=4), this sequence (b=5), A302090 (b=6).

Select[Range[1, 1000], PrimeQ[5*#^# + 4] &] (* Vaclav Kotesovec, Apr 01 2018 *)

for(n=0, 500, if(isprime(5*n^n+4), print1(n", ")))

lista(nn) = forstep(n=1, nn, 2, if(ispseudoprime(5*n^n+4), print1(n, ", "))); \\ Altug Alkan, Apr 01 2018

a(5) from Vaclav Kotesovec, Apr 01 2018

cp's OEIS Frontend