521730

Appears in sequences

• The number of closed lambda calculus terms of size n that have a normal form, where size(lambda M)=2+size(M), size(M N)=2+size(M)+size(N), and size(V)=1+i for a variable V bound by the i-th enclosing lambda.at n=30A333958
• Numbers k such that sigma(k) = psi(k) + phi(k) + tau(k)^2.at n=23A390421