This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A272652 #19 May 13 2016 16:27:45 %S A272652 0,14,134,4102,87112285931760246646623899502532662132742, %T A272652 1852673427797059126777135760139006525652319754650249024631321344126610074239106 %N A272652 a(n) is the smallest even number which has n inverse images under the map x -> x + (binary weight of x). %C A272652 If the word "even" is omitted the sequence is A230303. %C A272652 The next term is a(7) = 2^4233 + 130. %e A272652 The smallest number with two inverses is 14: the inverses are 11 = 1011_2 which maps to 11+3 = 14, and 12 = 1100_2 which maps to 12+2 = 14. %Y A272652 Cf. A230303, A000120, A092391, A228085. %K A272652 nonn %O A272652 1,2 %A A272652 _Max Alekseyev_ and _N. J. A. Sloane_, May 13 2016