A124755 Binomial sum of compositions in standard order.

0, 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 4, 6, 5, 8, 5, 5, 5, 6, 5, 7, 6, 9, 5, 8, 7, 11, 6, 11, 9, 16, 6, 6, 6, 7, 6, 8, 7, 10, 6, 9, 8, 12, 7, 12, 10, 17, 6, 10, 9, 14, 8, 14, 12, 20, 7, 14, 12, 22, 10, 20, 17, 32, 7, 7, 7, 8, 7, 9, 8, 11, 7, 10, 9, 13, 8, 13, 11, 18, 7, 11, 10, 15, 9, 15, 13, 21, 8, 15

Offset: 0

Author

Franklin T. Adams-Watters, Nov 06 2006

Keywords

• easy
• nonn
• tabf

Comments

The standard order of compositions is given by A066099.

This is the final term of the binomial transform of the composition.

Examples

			Composition number 11 is 2,1,1; 1*2+2*1+1*1 = 5, so a(11) = 5.
The table starts:
0
1
2 2
3 3 3 4
		

Links

• Alois P. Heinz, Rows n = 0..14, flattened

Crossrefs

Cf. A066099, A070939, A124756, A011782 (row lengths), A003462 (row sums).

Formula

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