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

Terms

a(0) =3a(1) =5a(2) =11a(3) =7a(4) =15a(5) =31a(6) =9a(7) =19a(8) =39a(9) =79a(10) =11a(11) =23a(12) =47a(13) =95a(14) =191a(15) =13a(16) =27a(17) =55a(18) =111a(19) =223a(20) =447a(21) =15a(22) =31a(23) =63a(24) =127a(25) =255a(26) =511a(27) =1023a(28) =17a(29) =35