OFFSET
1,2
COMMENTS
a(8) > 500000. - Robert Price, May 24 2014
FORMULA
a(n) = A061422(n) - 1.
MATHEMATICA
{ta={{0}}, tb={{0}}}; Do[g=n; s=2^n+n+1; If[PrimeQ[s], Print[n]; ta=Append[ta, n]; tb=Append[tb, s]], {n, 1, 10000}]; {ta, tb, g}
PROG
(PARI) is(n)=ispseudoprime(2^n+n+1) \\ Charles R Greathouse IV, Feb 20 2017
CROSSREFS
KEYWORD
hard,more,nonn
AUTHOR
Labos Elemer, Nov 19 2004
EXTENSIONS
New term 51380 from A061422 Max Alekseyev, Feb 08 2009
a(7) from Giovanni Resta, Mar 19 2014
STATUS
approved