A098124 Number of compositions of n in which the largest part is equal to the number of parts.

1, 0, 2, 1, 3, 6, 10, 15, 30, 54, 92, 160, 282, 492, 859, 1490, 2570, 4428, 7627, 13098, 22421, 38290, 65265, 111018, 188475, 319380, 540266, 912397, 1538371, 2589858, 4353820, 7309362, 12255474, 20523307, 34328731, 57357184, 95733131, 159626049

Offset: 1

Author

Vladeta Jovovic, Sep 25 2004

Keywords

• easy
• nonn

Examples

			a(7)=10 because we have 223, 232, 322, 133, 313, 331, 1114, 1141, 1411 and 4111.
		

Crossrefs

Cf. A077229, A047993.

Programs

Maple

G:=sum(((x^(k+1)-x)^k-(x^k-x)^k)/(x-1)^k,k=1..25):Gser:=series(G,x=0,45):seq(coeff(Gser,x^n),n=1..42); # Emeric Deutsch, Apr 16 2005

Formula

G.f.: Sum_{k>=1} ((x^(k+1)-x)^k - (x^k-x)^k)/(x-1)^k.

Extensions

More terms from Emeric Deutsch, Apr 16 2005