132361021domain: NAppears in sequencesa(n) is the smallest n-gonal pyramidal number greater than 1 which is also n-gonal; a(n) = 0 when one does not exist.at n=29A308488a(n) = (3*n^2 - 1) * (3*n^2 - 2) * (3*n^3 - 3*n + 1)/2.at n=10A344410Numbers that are simultaneously k-gonal and k-gonal pyramidal for some k >= 3.at n=27A373711