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.

A096583 Symmetric square array T(n,k)=T(k,n), read by antidiagonals, such that the n-th diagonal equals the convolution of the n-th row with the antidiagonal sums, with T(0,n)=1, for n>=0.

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 5, 5, 1, 1, 7, 8, 7, 1, 1, 9, 16, 16, 9, 1, 1, 11, 23, 20, 23, 11, 1, 1, 13, 35, 44, 44, 35, 13, 1, 1, 15, 46, 69, 44, 69, 46, 15, 1, 1, 17, 62, 99, 108, 108, 99, 62, 17, 1, 1, 19, 77, 147, 179, 96, 179, 147, 77, 19, 1, 1, 21, 97, 206, 272, 248, 248, 272, 206, 97, 21
Offset: 0

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Author

Paul D. Hanna, Jun 28 2004

Keywords

Comments

The main diagonal (A096585) equals the partial sums of the antidiagonal sums (A096584).

Examples

			Antidiagonal sums are A096584 =
[1,2,5,12,24,52,90,186,306,574,...];
convolution of antidiagonal sums and first row yields main diagonal:
A096585 = [1,3,8,20,44,96,186,372,678,...];
convolution of antidiagonal sums and second row yields secondary
diagonal:
[1,5,16,44,108,248,530,1088,2138,4068,...].
Rows begin:
[1,1,1,1,1,1,1,1,1,...],
[1,3,5,7,9,11,13,15,17,...],
[1,5,8,16,23,35,46,62,77,...],
[1,7,16,20,44,69,99,147,206,...],
[1,9,23,44,44,108,179,272,379,...],
[1,11,35,69,108,96,248,429,669,...],
[1,13,46,99,179,248,186,530,965,...],
[1,15,62,147,272,429,530,372,1088,...],
[1,17,77,206,379,669,965,1088,678,...],...
		

Crossrefs

Programs

  • PARI
    T(n,k)=if(n<0 || k<0,0,if(n==0 || k==0,1,if(n>k, sum(j=0,k,T(n-k,j)*sum(i=0,k-j,T(k-j-i,i))), sum(j=0,n,T(k-n,j)*sum(i=0,n-j,T(n-j-i,i))););))