

A098125


Number of compositions of n where the largest part is less than the number of parts.


2



0, 1, 1, 4, 8, 17, 38, 83, 174, 367, 771, 1606, 3324, 6849, 14054, 28743, 58605, 119161, 241717, 489345, 988945, 1995604, 4021710, 8095815, 16281400, 32716231, 65694106, 131833462, 264423116, 530128036, 1062424867, 2128513095
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OFFSET

1,4


LINKS



FORMULA

G.f.: Sum_{k>=0} ((x^kx)/(x1))^k.


EXAMPLE

a(5)=8 because we have 1112, 1121, 1211, 2111, 122, 212, 221 and 11111.


MAPLE

G:=sum(((x^kx)/(x1))^k, k=0..45): Gser:=series(G, x=0, 40): seq(coeff(Gser, x^n), n=1..36); # Emeric Deutsch, Apr 16 2005


CROSSREFS



KEYWORD

easy,nonn


AUTHOR



EXTENSIONS



STATUS

approved



