2,2

G.f.: [x^2(1+x)^2]/[(1-x)(1-x-x^2-x^3)].

Second differences of (A027026(n)-1)/2. Pairwise sums of A089068.

Adjacent sequences: A027050 A027051 A027052 this_sequence A027054 A027055 A027056

Sequence in context: A019454 A019453 A038089 this_sequence A122039 A083706 A074896

nonn

Clark Kimberling (ck6(AT)evansville.edu)