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 A071994 #9 Jan 16 2022 09:17:57
%S A071994 1,4,8,13,20,29,40,52,65,80,96,113,132,152,173,196,221,248,276,305,
%T A071994 336,369,404,440,477,516,557,600,644,689,736,784,833,884,936,989,1044,
%U A071994 1101,1160,1220,1281,1344,1408,1473,1540,1608,1677,1748,1821,1896,1972,2049
%N A071994 a(n) = Sum_{k=1..n} A003159(k).
%H A071994 Amiram Eldar, <a href="/A071994/b071994.txt">Table of n, a(n) for n = 1..10000</a>
%F A071994 a(n) ~ 3*n^2/4 + O(n*log(n)). - _Amiram Eldar_, Jan 16 2022
%t A071994 Accumulate @ Select[Range[100], EvenQ[IntegerExponent[#, 2]] &] (* _Amiram Eldar_, Jan 16 2022 *)
%Y A071994 Cf. A003159.
%K A071994 easy,nonn
%O A071994 1,2
%A A071994 _Benoit Cloitre_, Jun 17 2002