A249606 Primes of the form 2k^2 + k + 2.

2, 5, 23, 107, 173, 353, 467, 743, 1277, 1487, 2213, 2777, 3083, 10733, 14537, 15227, 17393, 18917, 21323, 22157, 23873, 33413, 36587, 38783, 42197, 50723, 54617, 71633, 94397, 101477, 112577, 118343, 122267, 128273, 130307, 140717, 149333, 174347, 203843

Offset

1,1

Links

Table of n, a(n) for n=1..39.

Example

k=0: 2*0^2 + 0 + 2 =  0 + 0 + 2 =   2.
k=1: 2*1^2 + 1 + 2 =  2 + 1 + 2 =   5.
k=3: 2*3^2 + 3 + 2 = 18 + 3 + 2 =  23.
k=7: 2*7^2 + 7 + 2 = 98 + 7 + 2 = 107.

Mathematica

Select[Table[2 n^2 + n + 2, {n, 0, 18000}], PrimeQ] (* Vincenzo Librandi, Nov 02 2014 *)

Prog

(PARI) for(k=0, 10^3, my(t=2*k^2+k+2); if(isprime(t), print1(t, ", "))); \\ Joerg Arndt, Nov 02 2014
(Magma) [a: n in [0..300] | IsPrime(a) where a is 2*n^2 + n + 2 ]; // Vincenzo Librandi, Nov 02 2014

Crossrefs

Sequence in context: A371308 A038833 A279819 * A003501 A006990 A358608

Adjacent sequences: A249603 A249604 A249605 * A249607 A249608 A249609

Keyword

nonn

Author

Jon E. Schoenfield, Nov 02 2014

Status

approved