0,2

a(n)=sum(C(k)*4^k, k=0..n), n>=0, with C(n):=A000108(n).

G.f.: c(4*x)/(1-x), where c(x):=(1-sqrt(1-4*x))/(2*x) is the o.g.f. of Catalan numbers A000108.

Fifth column (m=4) of triangle A112705.

Sequence in context: A006442 A084212 A004208 this_sequence A025168 A084358 A050351

Adjacent sequences: A112695 A112696 A112697 this_sequence A112699 A112700 A112701

nonn,easy

Wolfdieter Lang (wolfdieter.lang_AT_physik_DOT_uni-karlsruhe_DOT_de), Oct 31 2005