1048597domain: NAppears in sequencesa(n) = 2^n + n + 1.at n=20A005126Numbers of the form 2^k + k + 1 that are the product of two distinct primes.at n=6A176071Numerator of (0 followed by A005126(n)= 2, 4, 7, ...)/2^n.at n=21A271573Positions of 0 in A288132; complement of A288134.at n=21A288133