A117012 Primes of the form n^2+5n+c (n>=0), where c=3 for even n and c=-3 for odd n.

3, 17, 47, 107, 173, 269, 503, 641, 809, 983, 1187, 1637, 2441, 2753, 4157, 4547, 4967, 5393, 5849, 6311, 6803, 7829, 8363, 9497, 11981, 12653, 13331, 14753, 15497, 17027, 22943, 26723, 29753, 31859, 32933, 38609, 39791, 42221, 47297, 49943, 58313

Offset

1,1

Comments

Alternating Euler quadratic prime generating polynomial.

References

Harvey Cohn, Advanced Number Theory,Dover, New York, 1962, page 155.

Links

Table of n, a(n) for n=1..41.

Mathematica

f[n_] := If[Mod[n, 2] == 1, n^2 + 5*n - 3, n^2 + 5*n + 3] b = Flatten[Table[If[PrimeQ[f[n]] == True, f[n], {}], {n, 1, 100}]]

Prog

(PARI) m=250; for(n=1, m, k=n^2+5*n+3-6*(n%2); if(isprime(k), print1(k, ", ")))

Crossrefs

Cf. A014209, A082605.

Sequence in context: A106078 A087908 A152472 * A162291 A095697 A154304

Adjacent sequences: A117009 A117010 A117011 * A117013 A117014 A117015

Keyword

nonn

Author

Roger L. Bagula, Apr 16 2006

Extensions

Edited and extended by N. J. A. Sloane, Apr 17 2006

Status

approved