Triangle of odd-numbered terms in rows of Pascal's triangle.

Terms

a(0) =1a(1) =2a(2) =3a(3) =1a(4) =4a(5) =4a(6) =5a(7) =10a(8) =1a(9) =6a(10) =20a(11) =6a(12) =7a(13) =35a(14) =21a(15) =1a(16) =8a(17) =56a(18) =56a(19) =8a(20) =9a(21) =84a(22) =126a(23) =36a(24) =1a(25) =10a(26) =120a(27) =252a(28) =120a(29) =10