86640153600domain: NAppears in sequencesDiagonal A(n,n) of array A(k,n) = Product of first n of k-gonal pyramidal numbers.at n=4A140729a(n) = (5/6)^n*Gamma(n+3/5)*Gamma(n+1)*Gamma(n+2)/Gamma(3/5).at n=7A279663