OFFSET
1,2
COMMENTS
Number of k X l matrices with entries mod n, up to row and column permutation is Z(S_k X S_l; n,n,...) where Z(S_k X S_l; x_1,x_2,...) is cycle index of Cartesian product of symmetric groups S_k and S_l of degree k and l, respectively.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..1000
FORMULA
a(n)=(1/4!^2)*(n^16 + 12*n^12 + 36*n^10 + 67*n^8 + 160*n^6 + 204*n^4 + 96*n^2).
G.f.: -x*(x +1)*(x^14 +299*x^13 +84940*x^12 +6299584*x^11 +142482546*x^10 +1214416453*x^9 +4351647617*x^8 +6732281120*x^7 +4351647617*x^6 +1214416453*x^5 +142482546*x^4 +6299584*x^3 +84940*x^2 +299*x +1) / (x -1)^17. - Colin Barker, Jul 09 2013
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Vladeta Jovovic, Nov 04 2000
EXTENSIONS
More terms from Colin Barker, Jul 09 2013
STATUS
approved