Numbers n such that C(4n,n)/(3n+1) (A002293) is not divisible by 4.

Terms

a(0) =0a(1) =1a(2) =3a(3) =5a(4) =11a(5) =13a(6) =21a(7) =43a(8) =45a(9) =53a(10) =85a(11) =171a(12) =173a(13) =181a(14) =213a(15) =341a(16) =683a(17) =685a(18) =693a(19) =725a(20) =853a(21) =1365a(22) =2731a(23) =2733a(24) =2741a(25) =2773a(26) =2901a(27) =3413a(28) =5461a(29) =10923