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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A143632 Table T(n,k), n>=0, k>=0, read by antidiagonals, where the e.g.f. for column k satisfies A_k(x) = exp(x*A_k(((x+1)^k-1)/k)) if k>0 and A_0(x) = exp(x*A_0(0)) = exp(x).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 3, 16, 1, 1, 1, 3, 19, 125, 1, 1, 1, 3, 22, 185, 1296, 1, 1, 1, 3, 25, 253, 2541, 16807, 1, 1, 1, 3, 28, 329, 4256, 45787, 262144, 1, 1, 1, 3, 31, 413, 6471, 96727, 1037359, 4782969, 1, 1, 1, 3, 34, 505, 9216, 175747, 2828274, 28649553, 100000000, 1
Offset: 0

Views

Author

Alois P. Heinz, Aug 27 2008

Keywords

Examples

			Table begins:
  1,    1,    1,    1,    1,    1, ...
  1,    1,    1,    1,    1,    1, ...
  1,    3,    3,    3,    3,    3, ...
  1,   16,   19,   22,   25,   28, ...
  1,  125,  185,  253,  329,  413, ...
  1, 1296, 2541, 4256, 6471, 9216, ...
		

Crossrefs

Main diagonal gives A306578.

Programs

  • Maple
    A:= proc(n,k) option remember; if n<=0 or k=0 then 1 else A(n-1,k)(((x+1)^k-1)/k) fi; unapply(convert(series(exp(x*%), x,n+1), polynom), x) end: T:= (n,k)-> coeff(A(n,k)(x), x,n)*n!: seq(seq(T(n,d-n), n=0..d), d=0..11);
  • Mathematica
    a[n_, k_][x_] := Module[{f}, f = If[n <= 0 || k == 0, 1, a[n-1, k][((#+1)^k-1)/k]]&; Normal[Series[Exp[y*f[y]], {y, 0, n+1}]] /. y -> x]; t[n_, k_] := Coefficient[a[n, k][x], x, n]*n!; Table[t[n, d-n], {d, 0, 11}, {n, 0, d}] // Flatten (* Jean-François Alcover, Feb 12 2014, translated from Maple *)
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