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.

A107727 Matrix inverse of A107719.

Original entry on oeis.org

1, -1, 1, -3, -2, 1, -21, -7, -3, 1, -219, -53, -13, -4, 1, -2973, -583, -115, -21, -5, 1, -49323, -8249, -1437, -217, -31, -6, 1, -964173, -141655, -22715, -3101, -369, -43, -7, 1, -21680571, -2853185, -430877, -55251, -5975, -581, -57, -8, 1, -551173053, -65887783, -9505707, -1168349, -119137
Offset: 0

Views

Author

Paul D. Hanna, May 30 2005

Keywords

Comments

Matrix square is A107728. Matrix cube is A107726. Column 0 is negative A107716 shift right.

Examples

			Triangle begins:
1;
-1,1;
-3,-2,1;
-21,-7,-3,1;
-219,-53,-13,-4,1;
-2973,-583,-115,-21,-5,1;
-49323,-8249,-1437,-217,-31,-6,1;
-964173,-141655,-22715,-3101,-369,-43,-7,1; ...
		

Crossrefs

Programs

  • PARI
    {T(n,k)=local(L,N,M=matrix(n+1,n+1,m,j,if(m>=j,if(m==j,1,if(m==j+1,-3*j, polcoeff(1/sum(i=0,m-j,prod(r=0,i-1,3*r+1)*x^i)+O(x^m),m-j)))))^-1); L=sum(i=1,#M,(M^0-M)^i/i)/3;N=sum(i=0,#L,L^i/i!); return(if(n<0,0,N[n+1,k+1]))}