A059522 a(1) = 1, then a(n) = n*(n^(n-1)-1)*(n-2)!/(n-1).

1, 2, 12, 168, 4680, 223920, 16470720, 1725655680, 244074902400, 44799999955200, 10353389902732800, 2941340482417075200, 1007483754568427136000, 409436080665631065446400, 194769597399609368328192000, 107210375103315036907081728000, 67610055415398119744255815680000

Offset: 1

Author

N. J. A. Sloane, Feb 16 2001

Keywords

• nonn
• easy

Links

• Harry J. Smith, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A058128.

Programs

Magma

[1] cat [n*(n^(n-1)-1)*Factorial(n-2)/(n-1): n in [2..17]]; // Vincenzo Librandi, Feb 18 2020

Mathematica

Join[{1},Table[n(n^(n-1)-1) (n-2)!/(n-1),{n,2,20}]] (* Harvey P. Dale, Feb 17 2020 *)

PARI

{ for (n = 1, 200, if (n==1, a=1, a=n*(n^(n - 1) - 1)*(n - 2)!/(n - 1)); write("b059522.txt", n, " ", a); ) } \\ Harry J. Smith, Jun 27 2009

Formula

a(n) = (n-1)!*A058128(n), n>1.