A300947 Primes of form (2*k)! + k! + 1.

3, 727, 20922789928321, 403291461126605641811020801, 523022617466601111760007224221719391608832001

Offset: 1

Author

Seiichi Manyama, Mar 22 2018

Keywords

• nonn

Comments

The next term is too large to include.

Crossrefs

Cf. A088332, A118812, A242487.

Programs

Maple

select(isprime,[seq(factorial(2*k)+factorial(k)+1,k=0..600)]); # Muniru A Asiru, May 27 2018

PARI

lista(nn) = {for(k=0, nn, if(ispseudoprime(p=(2*k)!+k!+1), print1(p, ", ")));} \\ Altug Alkan, Mar 22 2018

Formula

a(n) = (2*A242487(n))! + A242487(n)! + 1.