A265013 Numbers n such that n*9^n + 1 is prime.

2, 12382, 27608, 31330, 117852

Offset: 1

Author

Tim Johannes Ohrtmann, Nov 30 2015

Keywords

• nonn
• more
• hard

Comments

All terms are even. - Robert Israel, Jan 18 2016

Crossrefs

Cf. A005849, A006552, A007646, A242176, A242177, A242178, A007647, A242196, A242197, A242198, A242199, A007648.

Programs

Magma

[n: n in [0..100000] | IsPrime(n*9^n+1)];

Mathematica

Select[Range[100000], PrimeQ[# 9^# + 1] &]

PARI

for(n=1,100000, if(isprime(n*9^n+1), print1(n,", ")))