40820

Appears in sequences

• Shifts left 2 places under "BHK" (reversible, identity, unlabeled) transform.at n=16A032104
• Number of quasi-Carmichael numbers less than 10^n.at n=7A263930
• G.f. A(x) satisfies A(x) = 1/( 1 - x*A(x*A(x)^4) ).at n=7A384649
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A384649.at n=43A384653