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

Terms

a(0) =1a(1) =1a(2) =3a(3) =1a(4) =6a(5) =7a(6) =1a(7) =9a(8) =21a(9) =15a(10) =1a(11) =12a(12) =42a(13) =60a(14) =31a(15) =1a(16) =15a(17) =70a(18) =150a(19) =155a(20) =63a(21) =1a(22) =18a(23) =105a(24) =300a(25) =465a(26) =378a(27) =127a(28) =1a(29) =21