204547domain: NAppears in sequencesFibonacci sequence beginning 29, 31.at n=19A157681a(n) = a(n-1) + a(n-2), for n>=2, with a(0)=27, a(1)=2.at n=21A190994a(n) = Sum_{d|n} (2*d)^(n/d - 1).at n=17A359134