A143081 A symmetrical triangle of coefficients based on A001147: a(n)=(2*n-1)*a(n-1); t(n,m)=a(n)^2/((2*n - 1)*a(m)*a(n - m)).
-1, 1, 1, 1, 3, 1, 3, 15, 15, 3, 15, 105, 175, 105, 15, 105, 945, 2205, 2205, 945, 105, 945, 10395, 31185, 43659, 31185, 10395, 945, 10395, 135135, 495495, 891891, 891891, 495495, 135135, 10395, 135135, 2027025, 8783775, 19324305, 24845535, 19324305, 8783775, 2027025, 135135, 2027025, 34459425
Offset: 1
Examples
{-1}, {1, 1}, {1, 3, 1}, {3, 15, 15, 3}, {15, 105, 175, 105, 15}, {105, 945, 2205, 2205, 945, 105}, {945, 10395, 31185, 43659, 31185, 10395, 945}, {10395, 135135, 495495, 891891, 891891, 495495, 135135, 10395}, {135135, 2027025, 8783775, 19324305, 24845535, 19324305, 8783775, 2027025, 135135}, {2027025, 34459425, 172297125, 447972525, 703956825, 703956825, 447972525, 172297125, 34459425, 2027025}, {34459425, 654729075, 3710131425, 11130394275, 20670732225, 25264228275, 20670732225, 11130394275, 3710131425, 654729075, 34459425}
Crossrefs
Cf. A001147.
Programs
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Mathematica
a[0] = 1; a[n_] := a[n] = (2*n - 1)*a[n - 1]; Table[Table[a[n]^2/((2*n - 1)*a[m]*a[n - m]), {m, 0, n}], {n, 0, 10}]; Flatten[%]
Formula
a(n)=(2*n-1)*a(n-1); t(n,m)=a(n)^2/((2*n - 1)*a(m)*a(n - m)).
Comments