

A129384


a(n)=sum{k=0..floor(n/2), C(nk,floor((nk)/2))}.


1



1, 1, 3, 5, 11, 19, 39, 71, 141, 261, 513, 965, 1889, 3585, 7017, 13417, 26287, 50527, 99147, 191399, 376155, 728619, 1434051, 2785667, 5489823, 10689199, 21089799, 41146383, 81262983, 158818311, 313935831, 614469591, 1215549981
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,3


COMMENTS

Partial sums of A129383.


LINKS

Table of n, a(n) for n=0..32.


FORMULA

G.f.: (1/(1x))(g(x)x*g(x^2)), g(x) the g.f. of A001405; a(n)=sum{k=floor((n+1)/2)..n, C(k,floor(k/2))}


MATHEMATICA

Table[Sum[Binomial[nk, Floor[(nk)/2]], {k, 0, Floor[n/2]}], {n, 0, 40}] (* Harvey P. Dale, Aug 21 2021 *)


CROSSREFS

Sequence in context: A320795 A285230 A089098 * A131887 A045691 A045961
Adjacent sequences: A129381 A129382 A129383 * A129385 A129386 A129387


KEYWORD

easy,nonn


AUTHOR

Paul Barry, Apr 12 2007


STATUS

approved



