564859072963domain: NAppears in sequencesa(n) = 1 + 2*3^(n-1) with a(0)=2.at n=25A052919Number of layers of dough separated by butter in successive foldings of croissant dough.at n=25A1007022*3^(n-1)-(-1)^n.at n=24A174132a(n) = 2*9^n+1.at n=12A199559