A075891 Quotient C[p(n),{p(n)+-1}/2]/p(n), where p(n)=n-th prime.

1, 2, 5, 42, 132, 1430, 4862, 58786, 2674440, 9694845, 477638700, 6564120420, 24466267020, 343059613650, 18367353072152, 1002242216651368, 3814986502092304, 212336130412243110, 3116285494907301262

Offset

2,2

Comments

A prime p divides all the binomial coefficients (save the extremes) in the p-th row of Pascal's triangle.

Same as Catalan( (p(n) - 1) / 2). - Jonathan Sondow, May 24 2013

Links

Table of n, a(n) for n=2..20.

Formula

a(n) = A000108( (A000040(n) - 1) / 2). - Jonathan Sondow, May 24 2013

Crossrefs

Cf. A000108.

Sequence in context: A042447 A176266 A075872 * A246669 A208302 A273398

Adjacent sequences: A075888 A075889 A075890 * A075892 A075893 A075894

Keyword

nonn

Author

Lekraj Beedassy, Oct 17 2002

Status

approved