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 A133147 #9 Mar 12 2025 09:39:50
%S A133147 1,2,5,8,19,30,41,52,115,178,241,304,367,430,493,556,1175,1794,2413,
%T A133147 3032,3651,4270,4889,5508,6127,6746,7365,7984,8603,9222,9841,10460,
%U A133147 21539,32618,43697,54776,65855,76934,88013,99092,110171,121250,132329
%N A133147 a(n) = a(n-1) + Sum_{k=0..floor(log_2(n-1))} a(2^k), a(1) = 1.
%e A133147 a(7) = a(6) + a(1)+a(2)+a(4) = 30 + 1+2+8 = 41;
%e A133147 a(8) = a(7) + a(1)+a(2)+a(4) = 41 + 1+2+8 = 52;
%e A133147 a(9) = a(8) + a(1)+a(2)+a(4)+a(8) = 52 + 1+2+8+52 = 115;
%e A133147 a(10) = a(9) + a(1)+a(2)+a(4)+a(8) = 115 + 1+2+8+52 = 178.
%t A133147 a[1]=1;a[n_]:=a[n-1]+Sum[a[2^k],{k,0,Floor[Log2[n-1]]}];Table[a[n],{n,43}] (* _James C. McMahon_, Mar 11 2025 *)
%K A133147 nonn
%O A133147 1,2
%A A133147 _Reinhard Zumkeller_, Dec 16 2007