0,3

Number of levels in all compositions of n+1 with only 1's and 2's.

S. Heubach and T. Mansour, Counting rises, levels, and drops in compositions

G.f.: x*(1+x^2)/(1-x-x^2)^2.

a:=n->sum(fibonacci(n), j=1..n): seq(a(n), n=0..33); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 25 2007

Partial sums: A014286. Cf. A000045.

Sequence in context: A122863 A034882 A137829 this_sequence A128020 A116562 A099495

Adjacent sequences: A045922 A045923 A045924 this_sequence A045926 A045927 A045928

nonn

Jeff Burch (gburch(AT)erols.com)