A153195 Number of primes <= n(n+1)(n+2)/6 (the tetrahedral numbers A000292).

0, 0, 2, 4, 8, 11, 16, 23, 30, 38, 47, 61, 72, 87, 102, 123, 141, 163, 189, 217, 242, 274, 306, 342, 378, 422, 462, 510, 560, 610, 663, 721, 782, 844, 914, 985, 1055, 1133, 1218, 1300, 1383, 1473, 1574, 1669, 1772, 1883, 1988, 2109, 2223, 2344, 2477, 2608, 2743

Offset

0,3

Links

Harry J. Smith, Table of n, a(n) for n = 0..10000

Prog

(Sage) [prime_pi(binomial(n, 3)) for n in range(2, 55)] # Zerinvary Lajos, Jun 06 2009

Crossrefs

Cf. A000292.

Sequence in context: A018600 A018408 A018320 * A354884 A279097 A279098

Adjacent sequences: A153192 A153193 A153194 * A153196 A153197 A153198

Keyword

nonn

Author

Harry J. Smith, Dec 20 2008, Dec 22 2008

Status

approved