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 A054600 #5 Aug 31 2024 15:15:32
%S A054600 0,2,4,14,16,42,76,142,256,554,1044,2070,4144,8218,16412,32934,65536,
%T A054600 131106,262372,524326,1048656,2097634,4194348,8388654,16777984,
%U A054600 33554642,67108916,134219390,268435568,536870970,1073745276,2147483710
%N A054600 Sum_{d|n, d odd} d*2^(n/d).
%t A054600 f[n_]:=With[{od=Select[Divisors[n],OddQ]},Total[od 2^(n/od)]]; Join[{0}, Array[f, 40]] (* _Harvey P. Dale_, Aug 31 2024 *)
%Y A054600 Cf. A054598-A054601, A000016, A000031.
%K A054600 nonn
%O A054600 0,2
%A A054600 _N. J. A. Sloane_, Apr 16 2000