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A131705
Phi(binomial(2*n,n)*n^3).
0
0, 1, 16, 144, 1536, 7200, 51840, 282240, 1474560, 7464960, 55296000, 200724480, 1051066368, 6167715840, 21459271680, 114960384000, 523197480960, 2214903398400, 9311791104000, 41500698624000, 183936614400000
OFFSET
0,3
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
KEYWORD
nonn
AUTHOR
Zerinvary Lajos, Oct 07 2007
STATUS
approved