A145140 Numerators of triangle T(n,k), n>=1, 0<=k<=n - 1, read by rows: T(n,k) is the coefficient of x^k in polynomial p_n for the n-th row sequence of A145153.

1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 11, 1, 1, 1, 6, 5, 7, 1, 1, 1, 5, 317, 5, 17, 1, 1, 1, 83, 27, 22, 7, 5, 1, 1, 2, 53, 5989, 1069, 1207, 7, 23, 1, 1, 3, 611, 2743, 93791, 149, 1213, 1, 13, 1, 1, 4, 101, 25523, 5419, 20071, 397, 3253, 1, 29, 1, 1, 5, 32419, 11017, 30731, 21757

Offset: 1

Author

Alois P. Heinz, Oct 03 2008

Keywords

• frac
• nonn
• tabl

Examples

			1, 0, 1, 0, 1/2, 1/2, 0, 1/3, 1/2, 1/6, 1, 1/4, 11/24, 1/4, 1/24, 1, 6/5, 5/12, 7/24, 1/12, 1/120, 1, 5/3, 317/360, 5/16, 17/144, 1/48, 1/720 ... = A145140/A145141
As triangle:
  1
  0 1
  0 1/2 1/2
  0 1/3 1/2 1/6
  1 1/4 11/24 1/4 1/24
  1 6/5 5/12 7/24 1/12 1/120
		

Crossrefs

Denominators of T(n, k): A145141. T(n, k)*(n-1)!: A145142.

Row sums give: A003269, A017898(n+3).

Cf. A145153, A000012, A001477, A000217, A000292, A145126, A145127, A145128, A145129, A145130.

Programs

Maple

row:= proc(n) option remember; local f,i,x; f:= unapply(simplify(sum('cat(a||i) *x^i', 'i'=0..n-1) ), x); unapply(subs(solve({seq(f(i+1)= coeftayl(x/ (1-x-x^4)/ (1-x)^i, x=0, n), i=0..n-1)}, {seq(cat(a||i), i=0..n-1)}), sum('cat(a||i) *x^i', 'i'=0..n-1) ), x); end: T:= (n,k)-> coeff(row(n)(x), x, k): seq(seq(numer(T(n,k)), k=0..n-1), n=1..14);

Mathematica

row[n_] := Module[{f, eq}, f = Function[x, Sum[a[k]*x^k, {k, 0, n-1}]]; eq = Table[f[k+1] == SeriesCoefficient[x/(1-x-x^4)/(1-x)^k, {x, 0, n}], {k, 0, n-1}]; Table[a[k], {k, 0, n-1}] /. Solve[eq] // First]; Table[row[n] // Numerator, {n, 1, 14}] // Flatten (* Jean-François Alcover, Feb 04 2014, after Alois P. Heinz *)

Formula

See program.