A195390 a(n) = (6*n)!

1, 720, 479001600, 6402373705728000, 620448401733239439360000, 265252859812191058636308480000000, 371993326789901217467999448150835200000000, 1405006117752879898543142606244511569936384000000000, 12413915592536072670862289047373375038521486354677760000000000

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..75

Formula

From Amiram Eldar, Apr 03 2021: (Start)

a(n) = A000142(A008588(n)).

Sum_{n>=0} 1/a(n) = A332892. (End)

Mathematica

(6*Range[0, 10])! (* Harvey P. Dale, Dec 16 2013 *)

Prog

(Magma) [Factorial(6*n): n in [0..10]]

Crossrefs

Cf. A000142, A008588, A010050, A100732, A100733, A100734, A271946, A332892.

Sequence in context: A003792 A208192 A258927 * A261427 A210280 A003926

Adjacent sequences: A195387 A195388 A195389 * A195391 A195392 A195393

Keyword

nonn,easy

Author

Vincenzo Librandi, Sep 24 2011

Status

approved