A060336 Number of n X n {-1,0,1} matrices modulo rows permutation (by symmetry this is the same as the number of {-1,0,1} matrices modulo columns permutation), i.e., the number of equivalence classes where two matrices A and B are equivalent if one of them is the result of permuting the rows of the other.

3, 45, 3654, 1929501, 7355513529, 212787633478239, 47937678641708357304, 85524882506287709213421693, 1224201212028616655577478516173315, 142132497715474639139076246298436794277130

Offset: 1

Author

Ahmed Fares (ahmedfares(AT)my-deja.com), Apr 25 2001

Keywords

• nonn

Links

• Harry J. Smith, Table of n, a(n) for n = 1..47

Crossrefs

A060690.

Programs

Mathematica

Table[Binomial[3^n+n-1,n],{n,10}] (* Harvey P. Dale, Apr 10 2012 *)

PARI

{ for (n=1, 47, write("b060336.txt", n, " ", binomial(3^n + n - 1, n)); ) } \\ Harry J. Smith, Jul 03 2009

Formula

a(n) = C(3^n + n - 1, n) (where C(n, k) denotes the binomial coefficient).

a(n) ~ 3^(n^2) / n!. - Vaclav Kotesovec, Jul 02 2016

Extensions

More terms from Harry J. Smith, Jul 03 2009