1,4

Primes certified using PFGW from Primeform group

Table of n, a(n) for n=1..22.

(10^1)*(2^5-1)+1=10*31+1=311 prime, 2^5-1=Mersenne-prime(3) so a(3)=1

Sequence in context: A278101 A120240 A179394 * A082361 A082363 A026177

Adjacent sequences: A102626 A102627 A102628 * A102630 A102631 A102632

nonn

Pierre CAMI, Feb 01 2005

approved