A208336 Triangle of coefficients of polynomials u(n,x) jointly generated with A208337; see the Formula section.
1, 1, 1, 1, 2, 2, 1, 3, 5, 3, 1, 4, 9, 10, 5, 1, 5, 14, 22, 20, 8, 1, 6, 20, 40, 51, 38, 13, 1, 7, 27, 65, 105, 111, 71, 21, 1, 8, 35, 98, 190, 256, 233, 130, 34, 1, 9, 44, 140, 315, 511, 594, 474, 235, 55, 1, 10, 54, 192, 490, 924, 1295, 1324, 942, 420, 89, 1, 11
Offset: 1
Examples
First five rows: 1 1...1 1...2...2 1...3...5...3 1...4...9...10...5 First five polynomials u(n,x): 1 1 + x 1 + 2x + 2x^2 1 + 3x + 5x^2 + 3x^3 1 + 4x + 9x^2 + 10x^3 + 5x^4
Programs
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Mathematica
u[1, x_] := 1; v[1, x_] := 1; z = 13; u[n_, x_] := u[n - 1, x] + x*v[n - 1, x]; v[n_, x_] := (x + 1)*u[n - 1, x] + x*v[n - 1, x]; Table[Expand[u[n, x]], {n, 1, z/2}] Table[Expand[v[n, x]], {n, 1, z/2}] cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; TableForm[cu] Flatten[%] (* A208336 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%] (* A208337 *) Table[u[n, x] /. x -> 1, {n, 1, z}] (* u row sums *) Table[v[n, x] /. x -> 1, {n, 1, z}] (* v row sums *) Table[u[n, x] /. x -> -1, {n, 1, z}](* u alt. row sums *) Table[v[n, x] /. x -> -1, {n, 1, z}](* v alt. row sums *)
Formula
u(n,x)=u(n-1,x)+x*v(n-1,x),
v(n,x)=(x+1)*u(n-1,x)+x*v(n-1,x),
where u(1,x)=1, v(1,x)=1.
T(n,k) = A038137(n-1,k). - Philippe Deléham, Apr 05 2012
Comments