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 A344835 #12 May 31 2021 02:11:32
%S A344835 0,1,1,2,1,2,3,2,2,3,4,3,2,3,4,5,4,3,3,4,5,6,5,4,3,4,5,6,7,6,5,6,6,5,
%T A344835 6,7,8,7,6,7,4,7,6,7,8,9,8,7,6,5,5,6,7,8,9,10,9,8,7,6,5,6,7,8,9,10,11,
%U A344835 10,9,12,7,7,7,7,12,9,10,11,12,11,10,13,8,7,6,7,8,13,10,11,12
%N A344835 Square array T(n, k), n, k >= 0, read by antidiagonals; T(n, k) = (n * 2^max(0, w(k)-w(n))) OR (k * 2^max(0, w(n)-w(k))) (where OR denotes the bitwise OR operator and w = A070939).
%C A344835 In other words, we right pad the binary expansion of the lesser of n and k with zeros (provided it is positive) so that both numbers have the same number of binary digits, and then apply the bitwise OR operator.
%H A344835 Rémy Sigrist, <a href="/A344835/b344835.txt">Table of n, a(n) for n = 0..10010</a>
%H A344835 Rémy Sigrist, <a href="/A344835/a344835.png">Colored representation of the table for n, k < 2^10</a>
%F A344835 T(n, k) = T(k, n).
%F A344835 T(m, T(n, k)) = T(T(m, n), k).
%F A344835 T(n, n) = n.
%F A344835 T(n, 0) = n.
%F A344835 T(n, 1) = max(1, n).
%e A344835 Array T(n, k) begins:
%e A344835 n\k| 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
%e A344835 ---+----------------------------------------------------------------
%e A344835 0| 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
%e A344835 1| 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
%e A344835 2| 2 2 2 3 4 5 6 7 8 9 10 11 12 13 14 15
%e A344835 3| 3 3 3 3 6 7 6 7 12 13 14 15 12 13 14 15
%e A344835 4| 4 4 4 6 4 5 6 7 8 9 10 11 12 13 14 15
%e A344835 5| 5 5 5 7 5 5 7 7 10 11 10 11 14 15 14 15
%e A344835 6| 6 6 6 6 6 7 6 7 12 13 14 15 12 13 14 15
%e A344835 7| 7 7 7 7 7 7 7 7 14 15 14 15 14 15 14 15
%e A344835 8| 8 8 8 12 8 10 12 14 8 9 10 11 12 13 14 15
%e A344835 9| 9 9 9 13 9 11 13 15 9 9 11 11 13 13 15 15
%e A344835 10| 10 10 10 14 10 10 14 14 10 11 10 11 14 15 14 15
%e A344835 11| 11 11 11 15 11 11 15 15 11 11 11 11 15 15 15 15
%e A344835 12| 12 12 12 12 12 14 12 14 12 13 14 15 12 13 14 15
%e A344835 13| 13 13 13 13 13 15 13 15 13 13 15 15 13 13 15 15
%e A344835 14| 14 14 14 14 14 14 14 14 14 15 14 15 14 15 14 15
%e A344835 15| 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15
%o A344835 (PARI) T(n, k, op=bitor, w=m->#binary(m)) = { op(n*2^max(0, w(k)-w(n)), k*2^max(0, w(n)-w(k))) }
%Y A344835 Cf. A003986, A070939.
%Y A344835 Cf. A344834 (AND), A344836 (XOR), A344837 (min), A344838 (max), A344839 (absolute difference).
%K A344835 nonn,base,tabl
%O A344835 0,4
%A A344835 _Rémy Sigrist_, May 29 2021