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A246148
Number of inequivalent n X 3 binary matrices, where equivalence means permutations of rows or columns or the symbol set.
2
1, 2, 8, 18, 47, 95, 200, 367, 674, 1142, 1914, 3040, 4765, 7189, 10702, 15487, 22135, 30949, 42794, 58143, 78216, 103723, 136338, 177081, 228201, 291119, 368790, 463149, 578011, 715946, 881810, 1078952, 1313462, 1589639, 1915028, 2295059, 2738985, 3253576
OFFSET
0,2
FORMULA
G.f.: (x^10 -x^9 +2*x^8 +x^7 +4*x^6 -2*x^5 +4*x^4 +x^3 +2*x^2 -x +1)/ ((x^2-x+1) *(x^2+x+1)^2 *(x+1)^4 *(x-1)^8).
MAPLE
a:= n-> coeff(series((x^10-x^9+2*x^8+x^7+4*x^6-2*x^5
+4*x^4+x^3+2*x^2-x+1)/((x^2-x+1) *(x^2+x+1)^2
*(x+1)^4 *(x-1)^8), x, n+1), x, n):
seq(a(n), n=0..50);
CROSSREFS
Column k=3 of A242093.
Sequence in context: A264054 A073307 A064009 * A201348 A102713 A332217
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Aug 17 2014
STATUS
approved