0,2

a(n)= A067297(2n+1)/2.

G.f.: A(x)= (f(y)-f(-y))/y with f(y) := (-1+9*y+(1+6*y)*c(y))/((1-y)*(1+5*y)*c(y)-1+11*y-y^2) where c(y) is g.f. of A000108 (Catalan) and y=4*sqrt(x).

Cf. A067320 (even indexed members of A067297).

Sequence in context: A136246 A113500 A064018 this_sequence A104652 A135787 A016793

Adjacent sequences: A067318 A067319 A067320 this_sequence A067322 A067323 A067324

nonn,easy

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Feb 5 2002