A176128 a(n) = (n*n!)^2.

1, 16, 324, 9216, 360000, 18662400, 1244678400, 104044953600, 10666233446400, 1316818944000000, 192795461591040000, 33039724723568640000, 6553108179373916160000, 1489610673484191498240000, 384752756862944870400000000, 112067362994533133451264000000, 36562414940103132183527424000000

Offset

1,2

Comments

Determinant of the 2 X 2 matrix M(1,1) = 1+(n!)^2, M(1,2)=M(2,1) = 1+n!*(n+1)!, M(2,2) = 1+((n+1)!)^2.

Links

Table of n, a(n) for n=1..17.

Formula

a(n) = (A001563(n))^2.

Example

a(1) = det(matrix([[2,3],[3,5]])) = 1.
a(2) = det(matrix([[5,13],[13,37]])) = 16.
a(3) = det(matrix([[37,145],[145,577]])) = 324.

Maple

seq((n*(n)!)^2, n=1..20) ;

Mathematica

Table[(n*n!)^2, {n, 20}] (* Harvey P. Dale, Jun 29 2020 *)

Prog

(PARI) a(n) = (n*n!)^2; \\ Michel Marcus, Feb 08 2025

Crossrefs

Cf. A001563.

Sequence in context: A276297 A229456 A246876 * A375223 A223394 A218476

Adjacent sequences: A176125 A176126 A176127 * A176129 A176130 A176131

Keyword

nonn,easy

Author

Michel Lagneau, Apr 09 2010

Extensions

More terms from Michel Marcus, Feb 08 2025

Status

approved