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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
3, 45, 3654, 1929501, 7355513529, 212787633478239, 47937678641708357304, 85524882506287709213421693, 1224201212028616655577478516173315, 142132497715474639139076246298436794277130 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

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

MATHEMATICA

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

PROG

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

CROSSREFS

A060690.

Sequence in context: A099168 A227379 A004105 * A268196 A057863 A302156

Adjacent sequences:  A060333 A060334 A060335 * A060337 A060338 A060339

KEYWORD

nonn

AUTHOR

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

EXTENSIONS

More terms from Harry J. Smith, Jul 03 2009

STATUS

approved

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Last modified September 27 21:12 EDT 2021. Contains 347698 sequences. (Running on oeis4.)