2146435072domain: NAppears in sequencesa(n) = 4^(n-1)*(2^n-1).at n=11A016152Number of subsets of {1,..,n} containing at least one prime.at n=30A089820a(n) = Sum_{d|n} Moebius(n/d)*d^(b-1)/phi(n) for b = 12.at n=7A160960Expansion of (1+16*x)/((1+4*x)*(1-8*x)).at n=10A271494a(n) = 2^n - 2^floor(2n/3).at n=31A291779