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.

A080246 Signed version of A035607.

Original entry on oeis.org

1, -2, 1, 2, -4, 1, -2, 8, -6, 1, 2, -12, 18, -8, 1, -2, 16, -38, 32, -10, 1, 2, -20, 66, -88, 50, -12, 1, -2, 24, -102, 192, -170, 72, -14, 1, 2, -28, 146, -360, 450, -292, 98, -16, 1, -2, 32, -198, 608, -1002, 912, -462, 128, -18, 1, 2, -36, 258, -952, 1970, -2364
Offset: 0

Views

Author

Paul Barry, Feb 15 2003

Keywords

Comments

Written as lower triangular matrix this has inverse A080247. Row sums are (1,-1,-1,1,1,-1,-1,1,1,...) Diagonal sums are signed tribonacci numbers A078042
Riordan array((1-x)/(1+x), x*(1-x)/(1+x)). - Philippe Deléham, Jan 05 2014

Examples

			Rows are {1}, {-2,1}, {2,-4,1}, {-2,8,-6,1}, ...
		

Crossrefs

Formula

Columns are generated by (1-x)^k/(1+x)^k
T(n,k)=(-1)^(n+k)*A113413(n,k). - Philippe Deléham, Jan 05 2014
T(n,k)=T(n-1,k-1)-T(n-1,k)-T(n-2,k-1), T(0,0)=1, T(1,0)=-2, T(1,1)=1, T(n,k)=0 if k<0 or if k>n. - Philippe Deléham, Jan 05 2014