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.

A244131 Triangle read by rows: terms T(n,k) of a binomial decomposition of n as Sum(k=0..n)T(n,k).

Original entry on oeis.org

0, 0, 1, 0, 4, -2, 0, 12, -18, 9, 0, 32, -108, 144, -64, 0, 80, -540, 1440, -1600, 625, 0, 192, -2430, 11520, -24000, 22500, -7776, 0, 448, -10206, 80640, -280000, 472500, -381024, 117649, 0, 1024, -40824, 516096, -2800000, 7560000, -10668672, 7529536, -2097152
Offset: 0

Views

Author

Stanislav Sykora, Jun 22 2014

Keywords

Comments

T(n,k)=(-k)^(k-1)*(1+k)^(n-k)*binomial(n,k) for k>0, while T(n,0)=0 by convention.

Examples

			First rows of the triangle, all summing up to n:
0,
0, 1,
0, 4, -2,
0, 12, -18, 9,
0, 32, -108, 144, -64,
0, 80, -540, 1440, -1600, 625,
		

Crossrefs

Programs

  • PARI
    seq(nmax, b)={my(v, n, k, irow);
    v = vector((nmax+1)*(nmax+2)/2); v[1]=0;
    for(n=1, nmax, irow=1+n*(n+1)/2; v[irow]=0;
      for(k=1, n, v[irow+k]=(-k*b)^(k-1)*(1+k*b)^(n-k)*binomial(n,k); ); );
    return(v); }
    a=seq(100,1);