19705

Appears in sequences

• Number of triangular regions in regular n-gon with all diagonals drawn.at n=32A062361
• Numbers k such that k + sigma(k) + sigma(sigma(k)) is a square.at n=37A116014
• a(2*n+1) = 7*a(n), a(2*n+2) = 8*a(n) + a(n-1).at n=33A116554
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, -1, 1), (-1, 1, 0), (1, 0, 0), (1, 1, 0)}.at n=8A150303
• Numbers k such that k!6 - 8 is prime, where k!6 is the sextuple factorial number (A085158).at n=43A289686
• a(n) = Sum_{k=1..n} tau(gcd(k,n))^gcd(k,n), where tau(n) is the number of divisors of n.at n=8A344194
• Triangle read by rows: T(n,k) is the number of labeled quasi-threshold graphs on vertex set [n] with k components, for n >= 1 and 1 <= k <= n.at n=22A350528
• Number of configurations of the 20 Vertex model on a square grid n X n with domain wall boundary conditions.at n=4A358069