147801

Appears in sequences

• Number of ways to build a contiguous building with n LEGO blocks of size 1 X 3 on top of a fixed block of the same size.at n=3A123774
• Sequence defined by the recurrence formula a(n+1)=sum(a(p)*a(n-p)+k,p=0..n)+l for n>=1, with here a(0)=1, a(1)=9, k=0 and l=1.at n=7A177130