Numbers k such that binomial(3k,k) is odd and not divisible by 5.

Terms

a(0) =0a(1) =1a(2) =5a(3) =8a(4) =16a(5) =33a(6) =40a(7) =41a(8) =65a(9) =66a(10) =80a(11) =81a(12) =128a(13) =130a(14) =133a(15) =138a(16) =165a(17) =325a(18) =328a(19) =330a(20) =640a(21) =641a(22) =650a(23) =656a(24) =658a(25) =1025a(26) =1026a(27) =1028a(28) =1033a(29) =1040