OFFSET
1,1
COMMENTS
First 18 terms are for n from 0 through 17, next terms are for n = 20, 22, 23, 25, 26, 27, 29, 30, 31, 32, 34, 35, 36, 37, 38, 40, ...
The sequence of n such that 4*n^2 + 4*n + 653 is composite starts 18, 19, 21, 24, 28, 33, 39, 46, 54, 60, 61, 62, 63, 65, 67, 72, 73, 75, 81, 82, 84, 85, 86, 93, 95, 96, 100, ...
These primes are in A000414. [Bruno Berselli, Apr 20 2014]
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Prime-Generating Polynomial
EXAMPLE
a(18) = 4*17^2 + 4*17 + 653 = 1877.
MATHEMATICA
Select[Table[4 n^2 + 4 n + 653, {n, 0, 100}], PrimeQ] (* Vincenzo Librandi, Apr 21 2014 *)
PROG
(PARI) {for(n=0, 50, if(isprime(p=4*n^2+4*n+653), print1(p, ", ")))}
(Magma) [a: n in [0..100] | IsPrime(a) where a is 4*n^2 + 4*n + 653]; // Vincenzo Librandi, Apr 21 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, Oct 04 2008
STATUS
approved