186270domain: NAppears in sequencesExpansion of e.g.f.: (exp(x/(1-x)) - 1)^2.at n=7A05283828-gonal pyramidal numbers: a(n) = n*(n+1)*(26*n-23)/6.at n=35A256648Triangle read by rows. T(n, k) = k! * Sum_{j=k..n} Lah(n, j) * Stirling2(j, k), where Lah(n, k) = A271703(n, k).at n=30A356654