A205616 Even numbers that are not the sum of two non-Ramanujan primes (A174635).

2, 4, 52, 70, 100, 124, 130, 148, 208, 232, 238, 292, 352, 418, 628

Offset

1,1

Comments

No other terms < 2*10^8. Conjectured to be complete.

Links

Table of n, a(n) for n=1..15.

Jonathan Sondow, Ramanujan primes and Bertrand's postulate, Amer. Math. Monthly, Vol. 116, No. 7 (2009), 630-635; arXiv preprint, arXiv:0907.5232 [math.NT], 2009-2010.

Jonathan Sondow, John W. Nicholson, and Tony D. Noe, Ramanujan Primes: Bounds, Runs, Twins, and Gaps, J. Integer Seq., Vol. 14 (2011), Article 11.6.2; arXiv preprint, arXiv:1105.2249 [math.NT], 2011.

Example

70 is a term because no two non-Ramanujan primes (A174635) sum to 70. 72 is not a term because 19 + 53 = 72. 19 and 53 are both non-Ramanujan primes.

Crossrefs

Cf. A104272, A174635, A173634, A204814, A205301, A205617, A205618.

Sequence in context: A211169 A085325 A082661 * A115587 A018337 A092389

Adjacent sequences: A205613 A205614 A205615 * A205617 A205618 A205619

Keyword

nonn,more

Author

John W. Nicholson and Donovan Johnson, Jan 30 2012

Status

approved