Triangle read by rows: T(n,k) = (2^k - 1)^n, 1<=k<=n.

Terms

a(0) =1a(1) =1a(2) =9a(3) =1a(4) =27a(5) =343a(6) =1a(7) =81a(8) =2401a(9) =50625a(10) =1a(11) =243a(12) =16807a(13) =759375a(14) =28629151a(15) =1a(16) =729a(17) =117649a(18) =11390625a(19) =887503681a(20) =62523502209a(21) =1a(22) =2187a(23) =823543a(24) =170859375a(25) =27512614111a(28) =1a(29) =6561a(30) =5764801a(31) =2562890625