6973568803domain: NAppears in sequencesa(n) = n*3^n + 1.at n=18A050914a(n) = 1 + 2*3^(n-1) with a(0)=2.at n=21A052919Number of layers of dough separated by butter in successive foldings of croissant dough.at n=21A1007022*3^(n-1)-(-1)^n.at n=20A174132a(n) = 2*9^n+1.at n=10A199559