A229492 Conjectured number of positive even numbers having exactly n representations as the unordered sum of two odd primes.

2, 3, 9, 11, 11, 16, 16, 18, 20, 23, 16, 29, 16, 25, 27, 23, 22, 25, 35, 29, 26, 25, 27, 27, 27, 33, 28, 44, 35, 21, 29, 35, 38, 33, 39, 37, 34, 35, 31, 31, 28, 41, 37, 32, 44, 35, 37, 41, 44, 33, 37, 32, 47, 39, 43, 47, 33, 37, 48, 41, 37, 48, 34, 35, 47, 36, 29

Offset

0,1

Comments

This sequence is closely related to the Goldbach conjecture, which is equivalent to a(0) = 2; that is, there are no numbers other than 2 and 4 that have no representations as the sum of two odd primes. This is sequence A000974, except for the first two terms.

Links

Table of n, a(n) for n=0..66.

Example

There are 3 even numbers with one representation: 6 = 3+3, 8 = 3+5, and 12 = 5+7. Hence, a(1) = 3.

Crossrefs

Cf. A000974 (using both even and odd primes).

Cf. A002375 (number of representations of 2n as the sum of two odd primes).

Sequence in context: A109636 A057236 A063257 * A328970 A103039 A140222

Adjacent sequences: A229489 A229490 A229491 * A229493 A229494 A229495

Keyword

nonn

Author

T. D. Noe, Oct 31 2013

Status

approved