OFFSET

1,1

COMMENTS

EXAMPLE

a(5) = 7.

7+4(1^2) = 7+4(1) = 7+4 = 11 which is prime.

7+4(2^2) = 7+4(4) = 7+16 = 23 which is prime.

7+4(3^2) = 7+4(9) = 7+36 = 43 which is prime.

7+4(4^2) = 7+4(16) = 7+64 = 71 which is prime.

7+4(5^2) = 7+4(25) = 7+100 = 107 which is prime.

MATHEMATICA

Flatten[Table[Select[Prime[Range[100]], And@@PrimeQ[Table[#+4n^2, {n, i}]]&, 1], {i, 19}]] (* Harvey P. Dale, Oct 04 2012 *)

CROSSREFS

KEYWORD

nonn

AUTHOR

Ray G. Opao, Mar 25 2004

STATUS

approved