2358720

Appears in sequences

• a(0) = a(1) = 1; thereafter a(n) = sigma(a(n-1)) + sigma(a(n-2)).at n=16A000458
• Number of rooted trees with 3 nodes of disjoint sets of labels with union {1..n}. If a node has an empty set of labels then it must have at least two children.at n=12A005173
• Numbers found in denominators of expansion of Airy function Bi(x).at n=9A014403
• a(n) = (n+1)*binomial(n+5, 5).at n=23A027810
• Triangle read by rows giving number of rooted labeled trees with n >= 2 nodes and height d >= 1.at n=34A034855
• a(n) = n!*(2*n-5)/2.at n=6A034860
• a(n) = (n + 4)*(n + 3)*(n + 2)*(n + 1)*n / 5 = 24*A000389(n+4).at n=24A158874
• Number of reduced words of length n in Coxeter group on 9 generators S_i with relations (S_i)^2 = (S_i S_j)^6 = I.at n=7A163953