655358domain: NAppears in sequencesa(n) = 5*2^n - 2.at n=17A051633Start with 1, then alternately add 2 or double.at n=35A123208a(n) = 5*2^(n-2) - 2 for n > 1, with a(1) = 1.at n=18A131051Row sums of triangle A134061.at n=17A134062Sums of two (not necessarily distinct) Mersenne primes (A000668).at n=26A171251