login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A077229 Number of compositions of n where the largest part is less than or equal to the number of parts. 8
1, 1, 1, 3, 5, 11, 23, 48, 98, 204, 421, 863, 1766, 3606, 7341, 14913, 30233, 61175, 123589, 249344, 502443, 1011366, 2033894, 4086975, 8206833, 16469875, 33035611, 66234372, 132745859, 265961487, 532717894, 1066778687, 2135822457, 4275459730, 8557335141, 17125445575, 34268965676, 68568213419, 137187103849, 274458924246 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..39.

Index entries for sequences related to compositions

FORMULA

G.f.: 1 + sum(k>=0, ((x^(k+1)-x)/(x-1))^k ). - Vladeta Jovovic, Sep 24 2004

G.f.: 1 + sum(n>=1, q^n * ( (1-q^n)/(1-q) )^n ), the g.f. above, slightly rewritten. [Joerg Arndt, Mar 30 2014]

a(n) ~ 2^(n-1). - Vaclav Kotesovec, May 01 2014

EXAMPLE

a(5)=11 since 5 can be written as 1+1+1+1+1, 1+1+1+2, 1+1+2+1, 1+1+3, 1+2+1+1, 1+2+2, 1+3+1, 2+1+1+1, 2+1+2, 2+2+1, or 3+1+1; but not as 2+3 since then the largest part (3) would be greater than the number of parts (2).

MATHEMATICA

Table[SeriesCoefficient[1 + Sum[x^k*((1-x^k)/(1-x))^k, {k, 1, n}], {x, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, May 01 2014 *)

CROSSREFS

Row sums of A077227.

Cf. A064174.

Sequence in context: A030494 A246491 A084361 * A335098 A018113 A113281

Adjacent sequences:  A077226 A077227 A077228 * A077230 A077231 A077232

KEYWORD

nonn

AUTHOR

Henry Bottomley, Oct 29 2002

EXTENSIONS

More terms from Vladeta Jovovic, Sep 24 2004

Prepended a(0) = 1, Joerg Arndt, Mar 30 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 22 13:48 EDT 2021. Contains 347607 sequences. (Running on oeis4.)