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 A078161 #13 Jun 18 2025 23:17:33
%S A078161 1,3,7,15,39,87,200,438,981,2135,4639,9971,21424,45699,97096,205563,
%T A078161 433895,913244,1917491,4016704,8397235,17521118,36497171,75900377,
%U A078161 157619705,326868209,676998896,1400510860,2894068715,5974185368,12320552102,25385332979
%N A078161 a(n) = A051201(2^n).
%t A078161 Table[ Apply[ Plus, Union[ Table[ Floor[2^w/j], {j, 1, 2^w}]]], {w, 1, 25}]
%Y A078161 Cf. A051201, A078159, A078160, A078162.
%K A078161 nonn
%O A078161 0,2
%A A078161 _Labos Elemer_, Nov 27 2002
%E A078161 Extended by _Robert G. Wilson v_, Dec 02 2002
%E A078161 Terms a(26) onward from _Max Alekseyev_, Feb 12 2012
%E A078161 a(0)=1 prepended by _Alois P. Heinz_, Oct 31 2023
%E A078161 a(21) corrected by _Sean A. Irvine_, Jun 18 2025