Number of sequences s of length n with s[1]=1, s[2]=1, s[j-1]<s[j]<=s[j-2]+s[j-1] for j>=3.

A005270

Number of sequences s of length n with s[1]=1, s[2]=1, s[j-1]<s[j]<=s[j-2]+s[j-1] for j>=3.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =6a(5) =27a(6) =177a(7) =1680a(8) =23009a(9) =455368a(10) =13067353a(11) =546378617a(12) =33472296082

External references