4292870144domain: NAppears in sequencesNumber of subsets of {1,..,n} containing at least one prime.at n=31A089820Numbers whose binary representation is the concatenation of n 1's and 2n-1 digits 0.at n=10A147538Expansion of 1/((1-4*x^2)^(3/2)-2*x*(1-4*x^2)).at n=21A270822a(n) = 2^n - 2^floor(2n/3).at n=32A291779