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.

A244117 Triangle read by rows: terms of a binomial decomposition of 1 as Sum(k=0..n)T(n,k).

Original entry on oeis.org

1, 0, 1, 0, 2, -1, 0, 3, -6, 4, 0, 4, -24, 48, -27, 0, 5, -80, 360, -540, 256, 0, 6, -240, 2160, -6480, 7680, -3125, 0, 7, -672, 11340, -60480, 134400, -131250, 46656, 0, 8, -1792, 54432, -483840, 1792000, -3150000, 2612736, -823543, 0, 9, -4608, 244944, -3483648, 20160000, -56700000, 82301184, -59295096, 16777216
Offset: 0

Views

Author

Stanislav Sykora, Jun 21 2014

Keywords

Comments

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

Examples

			First rows of the triangle, all summing up to 1:
1
0 1
0 2  -1
0 3  -6   4
0 4 -24  48  -27
0 5 -80 360 -540 256
		

Crossrefs

Programs

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