A292506 Number T(n,k) of multisets of exactly k nonempty binary words with a total of n letters such that no word has a majority of 0's; triangle T(n,k), n>=0, 0<=k<=n, read by rows.
1, 0, 1, 0, 3, 1, 0, 4, 3, 1, 0, 11, 10, 3, 1, 0, 16, 23, 10, 3, 1, 0, 42, 59, 33, 10, 3, 1, 0, 64, 134, 83, 33, 10, 3, 1, 0, 163, 320, 230, 98, 33, 10, 3, 1, 0, 256, 699, 568, 270, 98, 33, 10, 3, 1, 0, 638, 1599, 1451, 738, 291, 98, 33, 10, 3, 1, 0, 1024, 3434, 3439, 1935, 798, 291, 98, 33, 10, 3, 1
Offset: 0
Examples
T(4,2) = 10: {1,011}, {1,101}, {1,110}, {1,111}, {01,01}, {01,10}, {01,11}, {10,10}, {10,11}, {11,11}. Triangle T(n,k) begins: 1; 0, 1; 0, 3, 1; 0, 4, 3, 1; 0, 11, 10, 3, 1; 0, 16, 23, 10, 3, 1; 0, 42, 59, 33, 10, 3, 1; 0, 64, 134, 83, 33, 10, 3, 1; 0, 163, 320, 230, 98, 33, 10, 3, 1; 0, 256, 699, 568, 270, 98, 33, 10, 3, 1; 0, 638, 1599, 1451, 738, 291, 98, 33, 10, 3, 1; ...
Links
Crossrefs
Programs
-
Maple
g:= n-> 2^(n-1)+`if`(n::odd, 0, binomial(n, n/2)/2): b:= proc(n, i) option remember; expand(`if`(n=0 or i=1, x^n, add(binomial(g(i)+j-1, j)*b(n-i*j, i-1)*x^j, j=0..n/i))) end: T:= n-> (p-> seq(coeff(p,x,i), i=0..n))(b(n$2)): seq(T(n), n=0..12);
-
Mathematica
g[n_] := 2^(n-1) + If[OddQ[n], 0, Binomial[n, n/2]/2]; b[n_, i_] := b[n, i] = Expand[If[n == 0 || i == 1, x^n, Sum[Binomial[g[i] + j - 1, j]*b[n - i*j, i - 1]*x^j, {j, 0, n/i}]]]; T[n_] := Function[p, Table[Coefficient[p, x, i], {i, 0, n}]][b[n, n]]; Table[T[n], {n, 0, 12}] // Flatten (* Jean-François Alcover, Jun 06 2018, from Maple *)
Formula
G.f.: Product_{j>=1} 1/(1-y*x^j)^A027306(j).