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.

A101980 Matrix logarithm of A008459 (squared entries of Pascal's triangle), read by rows.

Original entry on oeis.org

0, 1, 0, -1, 4, 0, 4, -9, 9, 0, -33, 64, -36, 16, 0, 456, -825, 400, -100, 25, 0, -9460, 16416, -7425, 1600, -225, 36, 0, 274800, -463540, 201096, -40425, 4900, -441, 49, 0, -10643745, 17587200, -7416640, 1430016, -161700, 12544, -784, 64, 0, 530052880, -862143345, 356140800, -66749760, 7239456
Offset: 0

Views

Author

Paul D. Hanna, Dec 23 2004

Keywords

Comments

Column 0 (A101981) is essentially a signed offset version of A002190 and is related to Bessel functions. Row sums form A101982.

Examples

			Rows begin:
[0],
[1,0],
[ -1,4,0],
[4,-9,9,0],
[ -33,64,-36,16,0],
[456,-825,400,-100,25,0],
[ -9460,16416,-7425,1600,-225,36,0],
[274800,-463540,201096,-40425,4900,-441,49,0],
[ -10643745,17587200,-7416640,1430016,-161700,12544,-784,64,0],...
and equal the term-by-term product of column 0:
A101981 = {0,1,-1,4,-33,456,-9460,274800,-10643745,...}
with the rows of the squared Pascal's triangle (A008459):
[0],
[1*1^2, 0*1^2],
[ -1*1^2, 1*2^2, 0*1^2],
[4*1^2, -1*3^2, 1*3^2, 0*1^2],
[ -33*1^2, 4*4^2, -1*6^2, 1*4^2, 0*1^2],
[456*1^2, -33*5^2, 4*10^2, -1*10^2, 1*5^2, 0*1^2],...
		

Crossrefs

Programs

  • PARI
    {T(n,k)=if(nj,binomial(i-1,j-1)^2))^m/m)[n+1,k+1]))}

Formula

T(n, k) = A101981(n-k)*C(n, k)^2.