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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A101981 Column 0 of triangle A101980, which is the matrix logarithm of A008459 (squared entries of Pascal's triangle).

Original entry on oeis.org

0, 1, -1, 4, -33, 456, -9460, 274800, -10643745, 530052880, -32995478376, 2510382661920, -229195817258100, 24730000147369440, -3113066087894608560, 452168671458789789504, -75059305956331837485345, 14121026957032156557396000, -2988687741694684876495689040
Offset: 0

Views

Author

Paul D. Hanna, Dec 23 2004

Keywords

Comments

This sequence is a signed version of A002190 and is related to Bessel functions.

Crossrefs

Programs

  • Maple
    a:= n-> (-1)^(n+1)*coeff (series (-ln(BesselJ(0, 2*sqrt(x))), x, n+1), x, n)*(n!)^2: seq (a(n), n=0..30); # Alois P. Heinz, Oct 27 2012
  • Mathematica
    a[n_] := (-1)^(n+1) n!^2 SeriesCoefficient[-Log[BesselJ[0, 2 Sqrt[x]]], {x, 0, n}];
    Table[a[n], {n, 0, 18}] (* Jean-François Alcover, Jul 26 2018 *)
  • PARI
    {a(n)=sum(m=1,n,(-1)^(m-1)* (matrix(n+1,n+1,i,j,if(i>j,binomial(i-1,j-1)^2))^m/m)[n+1,1])}

Formula

a(n) = (-1)^(n+1)*A002190(n) for n>=0.
a(n) = 1 - Sum_{j=1..k-1} binomial(k, j)*binomial(k-1, j-1)*a(j) for n >= 1. See Günther & Schmidt link p.5. - Michel Marcus, Jun 17 2017

A101982 Row sums of triangle A101980, which is the matrix logarithm of A008459 (squared entries of Pascal's triangle).

Original entry on oeis.org

0, 1, 3, 4, 11, -44, 942, -23561, 806955, -35956868, 2023718198, -140435834681, 11782131588086, -1175694615277233, 137629159046661089, -18679508311308283526, 2909710453923000618155, -515605748075502971981108, 103130355820655917046896638, -23123715029010809457898920545
Offset: 0

Views

Author

Paul D. Hanna, Dec 23 2004

Keywords

Comments

A101981 is essentially a signed offset version of A002190 and is related to Bessel functions.

Crossrefs

Programs

  • PARI
    {a(n)=sum(k=0,n,sum(m=1,n,(-1)^(m-1)* (matrix(n+1,n+1,i,j,if(i>j,binomial(i-1,j-1)^2))^m/m)[n+1,k+1]))}

Formula

a(n) = Sum_{k=0..n} A101981(n-k)*C(n, k)^2.
Showing 1-2 of 2 results.