A060080 Scaled sums of squares.

1, 5, 56, 1080, 31680, 1310400, 72576000, 5181926400, 463325184000, 50697529344000, 6663103856640000, 1035678099456000000, 187913434365296640000, 39357424864287129600000, 9424067526124476825600000, 2558178330075402338304000000, 781407199004850168791040000000

Offset

1,2

Links

Harry J. Smith, Table of n, a(n) for n = 1..201 [offset shifted by Georg Fischer, May 11 2021]

Formula

a(n) = (Sum_{k=1..n} k^2)*((n-1)!)^2 = (n+1)!*(n-1)!*(2*n+1)/3!.

a(n) = A000330(n) * A001044(n-1).

Mathematica

Table[(n + 1)! (n - 1)! (2 n + 1) / 3!, {n, 1, 30}] (* Vincenzo Librandi Jul 04 2018 *)

Prog

(PARI) a(n) = { (n + 1)!*(n - 1)!*(2*n + 1)/6 } \\ Harry J. Smith, Jul 01 2009
(Magma) [Factorial(n+1) * Factorial(n-1) * (2*n+1)/6: n in [1..20]]; // Vincenzo Librandi, Jul 05 2018

Crossrefs

See Comments section at A060074.

Cf. A000330, A001044.

Sequence in context: A217819 A132618 A192562 * A203522 A180874 A336243

Adjacent sequences: A060077 A060078 A060079 * A060081 A060082 A060083

Keyword

nonn

Author

Wolfdieter Lang, Mar 16 2001

Extensions

Offset changed from 0 to 1 by Georg Fischer, May 09 2021

Status

approved