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.

A124756 Inverse binomial sum of compositions in standard order.

Original entry on oeis.org

0, 1, 2, 0, 3, 1, -1, 0, 4, 2, 0, 1, -2, -2, 1, 0, 5, 3, 1, 2, -1, -1, 2, 1, -3, -4, -1, -3, 2, 3, -1, 0, 6, 4, 2, 3, 0, 0, 3, 2, -2, -3, 0, -2, 3, 4, 0, 1, -4, -6, -3, -6, 0, 0, -4, -4, 3, 6, 2, 6, -2, -4, 1, 0, 7, 5, 3, 4, 1, 1, 4, 3, -1, -2, 1, -1, 4, 5, 1, 2, -3, -5, -2, -5, 1, 1, -3, -3, 4, 7, 3, 7, -1, -3, 2, 1, -5, -8, -5, -9, -2
Offset: 0

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Comments

The standard order of compositions is given by A066099.
This is the final term of the inverse binomial transform of the composition.

Examples

			Composition number 11 is 2,1,1; 1*2-2*1+1*1 = 1, so a(11) = 1.
The table starts:
0
1
2 0
3 1 -1 0
		

Crossrefs

Cf. A066099, A124754, A124755, A011782 (row lengths), A001477 (row sums).

Formula

For a composition b(1),...,b(k), a(n) = Sum_{i=1}^k (-1)^{i-1} C(k-1,i-1) b(i).