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.

Showing 1-4 of 4 results.

A294188 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f.: exp(k*(1/(1-x)^k - 1)).

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 4, 3, 0, 1, 9, 28, 13, 0, 1, 16, 117, 256, 73, 0, 1, 25, 336, 1881, 2848, 501, 0, 1, 36, 775, 8416, 35505, 37024, 4051, 0, 1, 49, 1548, 27925, 241696, 763209, 547936, 37633, 0, 1, 64, 2793, 75888, 1134025, 7769856, 18309861, 9064192
Offset: 0

Views

Author

Seiichi Manyama, Oct 24 2017

Keywords

Examples

			Square array A(n,k) begins:
   1,   1,     1,      1,       1, ...
   0,   1,     4,      9,      16, ...
   0,   3,    28,    117,     336, ...
   0,  13,   256,   1881,    8416, ...
   0,  73,  2848,  35505,  241696, ...
   0, 501, 37024, 763209, 7769856, ...
		

Crossrefs

Columns k=0..3 give A000007, A000262, A294189, A294190.
Rows n=0..1 give A000012, A000290.
Main diagonal gives A294192.

Formula

A(0,k) = 1 and A(n,k) = k^2 * (n-1)! * Sum_{j=1..n} binomial(j+k-1,k)*A(n-j,k)/(n-j)! for n > 0.

A294047 a(n) = n! * [x^n] exp(1/(1-x)^n - 1).

Original entry on oeis.org

1, 1, 10, 195, 6136, 280745, 17452296, 1406162695, 141881576320, 17464107109329, 2568781033444000, 444027365181074411, 88960718926056936960, 20419945656807380230105, 5317219394033953475875456, 1557341699638685065316319375, 509241278697083918035944964096
Offset: 0

Views

Author

Seiichi Manyama, Oct 22 2017

Keywords

Crossrefs

Main diagonal of A294046.

Programs

  • Maple
    S:=series(exp(1/(1-x)^n-1),x,31):
    seq(n!*coeff(S,x,n),n=0..30); # Robert Israel, Oct 22 2017
  • Mathematica
    Table[n!*SeriesCoefficient[Exp[1/(1-x)^n - 1], {x, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Oct 22 2017 *)

A294050 E.g.f.: exp(1/(1-x)^4 - 1).

Original entry on oeis.org

1, 4, 36, 424, 6136, 104544, 2037856, 44549824, 1076383296, 28423224064, 813041441536, 25012265117184, 822613038178816, 28777151476086784, 1066188308742567936, 41680239704335888384, 1713629127784250085376, 73882449584935612268544
Offset: 0

Views

Author

Seiichi Manyama, Oct 22 2017

Keywords

Crossrefs

Column k=4 of A294046.

Programs

  • Mathematica
    nmax = 20; CoefficientList[Series[Exp[1/(1-x)^4 - 1], {x, 0, nmax}], x] * Range[0, nmax]! (* Vaclav Kotesovec, Oct 22 2017 *)
  • PARI
    N=66; x='x+O('x^N); Vec(serlaplace(exp(1/(1-x)^4-1)))

A294051 Expansion of e.g.f.: exp(1/(1-x)^5 - 1).

Original entry on oeis.org

1, 5, 55, 785, 13705, 280745, 6561175, 171559925, 4947814225, 155676898925, 5297647127575, 193609855201625, 7554669411801625, 313185598385812625, 13735697420477200375, 634998741428031792125, 30844527567399706110625, 1569784302914751616023125
Offset: 0

Views

Author

Seiichi Manyama, Oct 22 2017

Keywords

Crossrefs

Column k=5 of A294046.

Programs

  • Mathematica
    nmax = 20; CoefficientList[Series[Exp[1/(1-x)^5 - 1], {x, 0, nmax}], x] * Range[0, nmax]! (* Vaclav Kotesovec, Oct 22 2017 *)
  • PARI
    N=66; x='x+O('x^N); Vec(serlaplace(exp(1/(1-x)^5-1)))

Formula

E.g.f.: exp(1/(1-x)^5 - 1).
Showing 1-4 of 4 results.