cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A268442 Triangle read by rows, the coefficients of the inverse Bell polynomials.

Original entry on oeis.org

1, 0, 1, 0, -1, 1, 0, 3, -1, -3, 1, 0, -15, 10, -1, 15, -4, -6, 1, 0, 105, -105, 10, 15, -1, -105, 60, -5, 45, -10, -10, 1, 0, -945, 1260, -280, -210, 35, 21, -1, 945, -840, 70, 105, -6, -420, 210, -15, 105, -20, -15, 1
Offset: 0

Views

Author

Peter Luschny, Feb 06 2016

Keywords

Comments

The triangle of coefficients of the Bell polynomials is A268441. For the definition of the inverse Bell polynomials see the link 'Bell transform'.

Examples

			[[1]],
[[0], [1]],
[[0], [-1],                    [1]],
[[0], [3, -1],                 [-3],           [1]],
[[0], [-15, 10, -1],           [15, -4],       [-6],      [1]],
[[0], [105, -105, 10, 15, -1], [-105, 60, -5], [45, -10], [-10], [1]]
Replacing the sublists by their sums reduces the triangle to the triangle of the Stirling numbers of first kind (A048994). The column 1 of sublists is A176740 (missing the leading 1) and A134685 in different order.
		

Crossrefs

Programs

  • Mathematica
    A268442Matrix[dim_] := Module[ {v, r, A},
    v = Table[Subscript[x,j],{j,1,dim}];
    r = Table[Subscript[x,j]->1,{j,1,n}];
    A = Table[Table[BellY[n,k,v], {k,0,dim}], {n,0,dim}];
    Table[Table[MonomialList[Inverse[A][[n,k]]/. r[[1]],
    v, Lexicographic] /. r, {k,1,n}] // Flatten, {n,1,dim}]];
    A268442Matrix[7] // Flatten
  • Sage
    # see link

A277394 Lagrange inversion, or reversion, for divided power series with odd powers only.

Original entry on oeis.org

1, -1, 10, -1, -280, 56, -1, 15400, -4620, 126, 120, -1, -1401400, 560560, -36036, -17160, 792, 220, -1, 190590400, -95295200, 10090080, 3203200, -126126, -360360, -50050, 1716, 2002, 364, -1
Offset: 1

Views

Author

Tom Copeland, Oct 12 2016

Keywords

Comments

Coefficients for partition polynomials for compositional inversion order-by-order of odd functions, e.g.f.s, or formal Taylor series f(x) = a1 x + a3 x^3/3! + a5 x^5/5! + ... .
The compositional inverse of f(x) is g(x)
= a1^(-1) [1] x
+ a1^(-4) [-1 a3] x^3/3!
+ a1^(-7) [10 a3^2 - 1 a1 a5] x^5/5!
+ a1^(-10)[-280 a3^3 + 56 a1 a3 a5 - a1^2 a7] x^7/7!
+ a1^(-13)[15400 a3^4 - 4620 a1 a3^2 a5 + a1^2 (126 a5^2 + 120 a3 a7) - a1^3 a9] * x^9/9! ... .

Crossrefs

Cf. A133437, A134264, A134685, A133932, A145271, A176740 for other inversion formulas.

Programs

  • Mathematica
    rows[nn_] := With[{s = InverseSeries[x + Sum[a[k] x^(2k+1)/(2k+1)!, {k, nn}] + O[x]^(2nn+2)]}, Table[(2n-1)! Coefficient[s, x^(2n-1) Product[a[w], {w, p}]], {n, nn}, {p, Reverse[Sort[Sort /@ IntegerPartitions[n-1]]]}]];
    rows[5] // Flatten (* Andrey Zabolotskiy, Mar 07 2024 *)

Extensions

Corrected and extended by Andrey Zabolotskiy, Mar 07 2024
Showing 1-2 of 2 results.