Numbers k such that both k and the k-th triangular number are binary palindromes.

Terms

a(0) =0a(1) =1a(2) =5a(3) =9a(4) =17a(5) =21a(6) =33a(7) =65a(8) =129a(9) =257a(10) =341a(11) =513a(12) =693a(13) =1025a(14) =1365a(15) =1397a(16) =2049a(17) =4097a(18) =8193a(19) =16385a(20) =21845a(21) =32769a(22) =43605a(23) =65537a(24) =87125a(25) =87381a(26) =131073a(27) =262145a(28) =524289a(29) =1048577