39261domain: NAppears in sequencesIntegers k such that k*28*c + 1 is prime for c = 1, 2, 4, 7 and 14.at n=17A067199Number of plane trees of total weight n of combinatorial class T=Z*U + Z*T^2/(1-T) with nodes Z of weight one and leaves U of weight three.at n=48A331106