A142048 Triangle of the denominators of the coefficients [x^k] P(n,x) defined in A141904.
1, 3, 1, 5, 3, 1, 7, 45, 1, 1, 9, 105, 15, 3, 1, 11, 1575, 945, 15, 3, 1, 13, 10395, 175, 945, 9, 1, 1, 15, 315315, 17325, 14175, 189, 15, 3, 1, 17, 45045, 23648625, 7425, 2835, 189, 15, 3, 1, 19, 6891885, 1576575, 23648625, 93555, 945, 135, 45, 1, 1, 21, 72747675, 7309575
Offset: 0
Crossrefs
Cf. A141904 (numerators).
Programs
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Mathematica
ClearAll[u, p]; u[n_] := (-1)^n/(2*n + 1); p[0][x_] := u[0]; p[n_][x_] := p[n][x] = u[n] + x*Sum[u[i]*p[n - i - 1][x] , {i, 0, n-1}] // Expand; row[n_] := CoefficientList[ p[n][x], x]; Table[row[n], {n, 0, 10}] // Flatten // Denominator (* Jean-François Alcover, Oct 02 2012 *)
Extensions
Edited and extended by R. J. Mathar, Aug 24 2009
Comments