A131705 Phi(binomial(2*n,n)*n^3).

0, 1, 16, 144, 1536, 7200, 51840, 282240, 1474560, 7464960, 55296000, 200724480, 1051066368, 6167715840, 21459271680, 114960384000, 523197480960, 2214903398400, 9311791104000, 41500698624000, 183936614400000

Offset

0,3

Links

Table of n, a(n) for n=0..20.

Maple

with(numtheory):with(combinat):a:=n->phi(binomial(2*n, n)*n^3): seq(a(n), n=0..22);

Mathematica

Table[EulerPhi[Binomial[2n, n]n^3], {n, 0, 20}] (* Harvey P. Dale, May 10 2015 *)

Crossrefs

Cf. A005429.

Sequence in context: A287168 A155663 A077485 * A203538 A370849 A076029

Adjacent sequences: A131702 A131703 A131704 * A131706 A131707 A131708

Keyword

nonn

Author

Zerinvary Lajos, Oct 07 2007

Status

approved