A131681 Phi(binomial(2*n,n)*n^2) (phi of A002736 = Apery numbers: n^2 C(2n,n). ).

0, 1, 8, 48, 384, 1440, 8640, 40320, 184320, 829440, 5529600, 18247680, 87588864, 474439680, 1532805120, 7664025600, 32699842560, 130288435200, 517321728000, 2184247296000, 9196830720000, 38626689024000, 188841590784000

Offset

0,3

Links

Table of n, a(n) for n=0..22.

Maple

with(numtheory):with(combinat):a:=n->phi(binomial(2*n, n)*n^2): seq(a(n), n=0..25);

Crossrefs

Cf. A002736.

Sequence in context: A200161 A172111 A144014 * A077708 A165041 A165049

Adjacent sequences: A131678 A131679 A131680 * A131682 A131683 A131684

Keyword

nonn

Author

Zerinvary Lajos, Oct 07 2007

Status

approved