A055599 Triangle T(n,k) read by rows, giving the number of n X n binary matrices with no zero rows or columns and with k=0..n^2 ones.
0, 1, 0, 0, 2, 4, 1, 0, 0, 0, 6, 45, 90, 78, 36, 9, 1, 0, 0, 0, 0, 24, 432, 2248, 5776, 9066, 9696, 7480, 4272, 1812, 560, 120, 16, 1, 0, 0, 0, 0, 0, 120, 4200, 43000, 222925, 727375, 1674840, 2913100, 3995100, 4441200, 4073100, 3114140, 1994550
Offset: 1
Examples
For m=n=3 we get T(3,k)=C(9,k)-6*C(6,k)+9*C(4,k)+6*C(3,k)-18*C(2,k)+9*C(1,k)-C(0,k) giving the batch [0,0,0,6,45,90,78,36,9,1]. Triangle begins: 0, 1, 0, 0, 2, 4, 1, 0, 0, 0, 6, 45, 90, 78, 36, 9, 1, 0, 0, 0, 0, 24, 432, 2248, 5776, 9066, 9696, 7480, 4272, 1812, 560, 120, 16, 1, ...
Links
- H. Cheballah, S. Giraudo, and R. Maurice, Combinatorial Hopf algebra structure on packed square matrices, arXiv preprint arXiv:1306.6605 [math.CO], 2013.
- Stephan Mertens, Domination Polynomial of the Rook Graph, JIS 27 (2024) 24.3.7; arXiv:2401.00716 [math.CO], 2024.
- Roberto Tauraso, Edge cover time for regular graphs, JIS 11 (2008) 08.4.4
- Eric Weisstein's World of Mathematics, Complete Bipartite Graph
- Eric Weisstein's World of Mathematics, Edge Cover Polynomial
Crossrefs
Cf. A048291 (row sums).
Programs
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Mathematica
row[n_] := Sum[(-1)^(n-k) Binomial[n, k] ((1+x)^k - 1)^n, {k, 0, n}] + O[x]^(n^2+1) // CoefficientList[#, x]&; Table[row[n], {n, 1, 5}] // Flatten (* Jean-François Alcover, Nov 06 2018 *)
Formula
Number of m X n binary matrices with no zero rows or columns and with k=0..m*n ones is Sum_{i=0..n} (-1)^i*C(n, i)*a(m, n-i, k) where a(m, n, k)=Sum_{i=0..m} (-1)^i*C(m, i)*C((m-i)*n, k).
G.f. for n-th row: Sum_{k=0..n} (-1)^(n-k)*binomial(n, k)*((1+x)^k-1)^n. - Vladeta Jovovic, Apr 04 2003
E.g.f.: Sum(((1+y)^n-1)^n*exp((1-(1+y)^n)*x)*x^n/n!,n=0..infinity). - Vladeta Jovovic, Feb 24 2008
Comments