Numbers k whose binary expansion is a substring of the binary expansion of binomial(k,2).

Terms

a(0) =3a(1) =5a(2) =9a(3) =11a(4) =17a(5) =33a(6) =44a(7) =50a(8) =58a(9) =65a(10) =129a(11) =257a(12) =396a(13) =452a(14) =513a(15) =581a(16) =864a(17) =971a(18) =1025a(19) =1139a(20) =1843a(21) =1881a(22) =1914a(23) =2049a(24) =2541a(25) =2676a(26) =2929a(27) =3130a(28) =4097a(29) =4596