128544domain: NAppears in sequencesEnneagonal numbers whose sum of digits is also enneagonal.at n=24A117051a(n) = 3*(2*n - 1)*( 3*(2*n - 1)^3 + 1) / 2.at n=6A355752Number of 4 X 4 prime magic squares with magic sum 2n.at n=42A368676Number of spanning trees of the class H_3.at n=5A386907