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 A333906 #16 Apr 28 2020 00:14:22
%S A333906 1,1,3,5,5,3,7,13,17,19,19,17,13,7,15,29,41,51,59,65,69,71,71,69,65,
%T A333906 59,51,41,29,15,31,61,89,115,139,161,181,199,215,229,241,251,259,265,
%U A333906 269,271,271,269,265,259,251,241,229,215,199,181,161
%N A333906 For n >= 2, a(n) = Sum_{k=2..n} prevpower2(k) + nextpower2(k) - 2*k, where prevpower2(k) is the largest power of 2 < k, nextpower2(k) is the smallest power of 2 > k.
%C A333906 Partial sums of b(k) = prevpower2(k) + nextpower2(k) - 2*k; b(k) = 0 for A007283.
%e A333906 a(2) = (1 + 4 - 2*2) = 1;
%e A333906 a(3) = (1 + 4 - 2*2) + (2 + 4 - 2*3) = 1;
%e A333906 a(4) = (1 + 4 - 2*2) + (2 + 4 - 2*3) + (2 + 8 - 2*4) = 3.
%Y A333906 Cf. A000079, A007283, A062050, A080079.
%K A333906 nonn
%O A333906 2,3
%A A333906 _Ctibor O. Zizka_, Apr 09 2020