871696101

Appears in sequences

• Number of closed walks of length n along the edges of a tetrahedron based at a vertex.at n=20A054878
• Closed walks of length 2n along the edges of a cube based at a vertex.at n=10A054879
• Binomial transform of (1,-1,4,-16,64,-256,1024,...) = (3*0^n-(-4)^n)/4.at n=20A084567
• a(n) = (2 + (-1)^n + 3^n)/4.at n=20A122983
• a(n) = 3*a(n-1) - a(n-3) + 3*a(n-4), with initial values 1,3,7,20.at n=19A132868
• Numbers occurring in A137822 : first differences of numbers n such that 3 | sum( Catalan(k), k=1..2n).at n=29A137823