A100358 Numbers n such that 2^n+n^3+1 is prime.

0, 2, 6, 8, 20, 38, 96, 146, 236, 458, 726, 962, 1422, 2864, 3858, 5228, 9822, 21774, 32336, 33336, 43556

Offset: 1

Author

Labos Elemer, Nov 19 2004

Keywords

• more
• nonn

Comments

a(22) > 200000. - Giovanni Resta, Mar 23 2014

a(22) > 400000. - Robert Price, Sep 01 2014

Crossrefs

Cf. A001580, A069539, A100357.

Programs

Maple

A100358:=n->`if`(isprime(2^n+n^3+1),n,NULL): seq(A100358(n), n=0..10^3); # Wesley Ivan Hurt, Sep 01 2014

Mathematica

{ta={{0}}, tb={{0}}}; Do[g=n;s=2^n+n^3+1;If[PrimeQ[s], Print[n];ta=Append[ta, n];tb=Append[tb, s]], {n, 1, 10000}];{ta, tb, g}

PARI

for(n=1,10^5,if(ispseudoprime(2^n+n^3+1),print1(n,", "))) \\ Derek Orr, Sep 01 2014

Extensions

a(17)-a(21) from Giovanni Resta, Mar 23 2014