161579domain: NAppears in sequencesa(n) = (12*n+1)*(12*n+11).at n=33A001538Numbers n such that the decimal representation of n is contained as substring in that of the n-th pentagonal number.at n=21A179782a(n) = [x^n] Product_{k>=1} (1 + x^k)^tau_n(k), where tau_n(k) = number of ordered n-factorizations of k.at n=11A321192