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.

A059881 As upper right triangle: wiggly sums to n where first term is k (sums in which terms alternately increase and decrease or vice versa; zigzag and zagzig partitions).

Original entry on oeis.org

1, 0, 1, 1, 1, 1, 2, 0, 1, 1, 2, 2, 1, 1, 1, 4, 4, 1, 1, 1, 1, 6, 5, 3, 2, 1, 1, 1, 9, 8, 5, 2, 2, 1, 1, 1, 14, 13, 9, 4, 3, 2, 1, 1, 1, 23, 19, 14, 8, 3, 3, 2, 1, 1, 1, 35, 31, 20, 13, 7, 4, 3, 2, 1, 1, 1, 55, 49, 32, 20, 12, 6, 4, 3, 2, 1, 1, 1, 87, 76, 50, 32, 18, 11, 7, 4, 3, 2, 1, 1, 1, 136
Offset: 1

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Author

Henry Bottomley, Feb 05 2001

Keywords

Examples

			Rows start (1,0,1,2,2,...), (1,1,0,2,...), (1,1,1,...) etc. T(10,4)=8 since 10 can be written as 4+6, 4+5+1, 4+2+4, 4+2+3+1, 4+1+5, 4+1+4+1, 4+1+3+2, or 4+1+2+1+2.
		

Crossrefs

Column sums are A025047. Cf. A025048, A025049, A059882, A059883.

Formula

T(n, k) =A059882(n, k)+A059883(n, k) if n>k>0; T(n, n)=1 if n>0.