A216428 Primes of the form 2^(n-1)*(n+1)^2-(-1)^n.

5, 17, 199, 577, 1567, 25601, 147457, 346111, 47316991, 104857601, 231211007, 1109393407, 11341398017, 52613349377, 4964982194177, 10522669875199, 5125690732661117028219823849471

Offset

1,1

Comments

Generated by n: 1, 2, 4, 5, 6, 9, 11, 12, 18, 19, 20, 22, 25, 27, 33, 34, 90, 110, 111, 287, 424, 767, 1091, 2134,...

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..26

Example

a(1) = 2^(1 - 1)*(1 + 1)^2 - (-1)^1 = 5.
a(2) = 2^(2 - 1)*(2 + 1)^2 - (-1)^2 = 17.
a(3) = 2^(4 - 1)*(4 + 1)^2 - (-1)^4 = 199.
a(4) = 2^(5 - 1)*(5 + 1)^2 - (-1)^5 = 577.

Mathematica

Select[Table[2^(n - 1) (n + 1)^2 - (-1)^n, {n, 300}], PrimeQ] (* Vincenzo Librandi, Sep 10 2012 *)

Prog

(Magma) [a: n in [1..100] | IsPrime(a) where a is 2^(n-1)*(n+1)^2 - (-1)^n]; // Vincenzo Librandi, Sep 10 2012

Crossrefs

Cf. A216362.

Sequence in context: A090645 A206328 A096407 * A062230 A103920 A086362

Adjacent sequences: A216425 A216426 A216427 * A216429 A216430 A216431

Keyword

nonn,less

Author

Juri-Stepan Gerasimov, Sep 07 2012

Status

approved