A046926 Number of ways to express n as p+2q; p, q primes.

0, 0, 0, 0, 0, 1, 1, 1, 2, 0, 2, 1, 2, 0, 2, 1, 4, 0, 2, 0, 3, 0, 3, 1, 3, 0, 4, 1, 4, 0, 2, 0, 5, 0, 3, 1, 4, 0, 4, 1, 5, 0, 4, 0, 6, 0, 4, 1, 4, 0, 7, 0, 5, 0, 3, 0, 7, 0, 3, 1, 3, 0, 7, 1, 7, 0, 5, 0, 7, 0, 4, 0, 4, 0, 8, 1, 7, 0, 5, 0, 8, 0, 4, 1, 7, 0, 8, 1, 7, 0, 4, 0, 11, 0, 5, 1, 6, 0, 9

Offset

1,9

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

L. Hodges, A lesser-known Goldbach conjecture, Math. Mag., 66 (1993), 45-47.

Index entries for sequences related to Goldbach conjecture

Prog

(PARI) a(n)=my(s); forprime(p=2, n\2-1, if(isprime(n-2*p), s++)); s \\ Charles R Greathouse IV, Jul 22 2015

Crossrefs

Sequence in context: A353698 A341345 A068067 * A200815 A074398 A144765

Adjacent sequences: A046923 A046924 A046925 * A046927 A046928 A046929

Keyword

nonn

Author

David W. Wilson

Status

approved