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 A306903 #16 Mar 19 2019 04:34:45 %S A306903 0,1,2,7,8,19,26,61,70,126,146,270,308,519,604,1054,1222,1929,2208, %T A306903 3454,3930,5862,6576,9833,11102,16052,17904,25752,28764,40479,44830, %U A306903 62988,70188,97151,107662,148141,164710,223783,247380,334035,370406,495313,547000 %N A306903 Sum over all partitions of n of the bitwise XOR of the parts. %H A306903 Alois P. Heinz, <a href="/A306903/b306903.txt">Table of n, a(n) for n = 0..1000</a> %H A306903 Wikipedia, <a href="https://en.wikipedia.org/wiki/Bitwise operation">Bitwise operation</a> %H A306903 Wikipedia, <a href="https://en.wikipedia.org/wiki/Commutative_property">Commutative property</a> %H A306903 Wikipedia, <a href="https://en.wikipedia.org/wiki/Identity_element">Identity element</a> %H A306903 Wikipedia, <a href="https://en.wikipedia.org/wiki/Partition_(number_theory)">Partition (number theory)</a> %H A306903 Wikipedia, <a href="https://en.wikipedia.org/wiki/Truth_table">Truth table</a> %F A306903 a(n) is odd <=> n in { A067567 }. %p A306903 b:= proc(n, i, r) option remember; `if`(i<1, 0, (t-> %p A306903 `if`(i<n, b(n-i, min(i, n-i), t), 0)+ %p A306903 `if`(i=n, t, 0)+b(n, i-1, r))(Bits[Xor](i, r))) %p A306903 end: %p A306903 a:= n-> b(n$2, 0): %p A306903 seq(a(n), n=0..45); %Y A306903 Cf. A006906, A066186, A067567, A306884, A306895, A306901, A306902, A306925. %K A306903 nonn,base %O A306903 0,3 %A A306903 _Alois P. Heinz_, Mar 15 2019