A221207 Primes of the form 2^(n-2)*(n+2)^2 + 1.

2, 17, 2593, 5308417, 26214401, 57802753, 584652423169, 5566277615617, 24807731101697, 2128654511374337, 114923510727115685920505857, 626707144888223764167681638401, 28901765777295687591430290881352276511750619137

Offset

1,1

Links

Table of n, a(n) for n=1..13.

Example

a(0) = 2 = 2^(0-2)*(0+2)^2 + 1 = (1/4) * 4 + 1.

Mathematica

Select[Table[2^(n - 2)*(n + 2)^2 + 1, {n, 0, 200}], PrimeQ] (* T. D. Noe, Apr 05 2013 *)

Prog

(PARI) for(n=0, 1e3, is(ispseudoprime(t=2^(n-2)*(n + 2)^2+1), print1(t", "))) \\ Charles R Greathouse IV, Mar 18 2014

Crossrefs

Sequence in context: A284706 A092415 A274053 * A274015 A279884 A060353

Adjacent sequences: A221204 A221205 A221206 * A221208 A221209 A221210

Keyword

nonn,less

Author

Irina Gerasimova, Feb 21 2013

Status

approved