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 A104258 #16 Aug 02 2022 12:39:08
%S A104258 1,2,4,16,26,42,57,512,730,1010,1343,1872,2367,2954,3616,65536,83522,
%T A104258 104994,130341,160400,194923,234762,280394,345600,406251,474578,
%U A104258 551152,637392,732512,837930,954305,33554432,39135394,45435458
%N A104258 Replace 2^i with n^i in binary representation of n.
%C A104258 The following sequences all appear to have the same parity: A003071, A029886, A061297, A092524, A093431, A102393, A104258, A122248, A128975. - _Jeremy Gardiner_, Dec 28 2008
%H A104258 Michael S. Branicky, <a href="/A104258/b104258.txt">Table of n, a(n) for n = 1..10000</a>
%F A104258 a(n) = A104257(n, n).
%F A104258 a(n) = [x^n] (1/(1 - x)) * Sum_{k>=0} n^k*x^(2^k)/(1 + x^(2^k)). - _Ilya Gutkovskiy_, Aug 17 2019
%o A104258 (PARI) a(n) = my(b=binary(n)); sum(k=1, #b, b[k]*n^(#b-k)); \\ _Michel Marcus_, Mar 19 2015
%o A104258 (Python)
%o A104258 def a(n): return sum(n**i*int(bi) for i, bi in enumerate(bin(n)[2:][::-1]))
%o A104258 print([a(n) for n in range(1, 35)]) # _Michael S. Branicky_, Aug 02 2022
%Y A104258 Cf. A104257.
%K A104258 nonn,base
%O A104258 1,2
%A A104258 _Ralf Stephan_, Mar 05 2005