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 A344838 #9 May 31 2021 02:11:35
%S A344838 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 A344838 6,7,8,7,6,6,4,6,6,7,8,9,8,7,6,5,5,6,7,8,9,10,9,8,7,6,5,6,7,8,9,10,11,
%U A344838 10,9,12,7,6,6,7,12,9,10,11,12,11,10,12,8,7,6,7,8,12,10,11,12
%N A344838 Square array T(n, k), n, k >= 0, read by antidiagonals; T(n, k) = max(n * 2^max(0, w(k)-w(n)), k * 2^max(0, w(n)-w(k))) (where w = A070939).
%C A344838 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 take the greatest value.
%H A344838 Rémy Sigrist, <a href="/A344838/b344838.txt">Table of n, a(n) for n = 0..10010</a>
%H A344838 Rémy Sigrist, <a href="/A344838/a344838.png">Colored representation of the table for n, k < 2^10</a>
%F A344838 T(n, k) = T(k, n).
%F A344838 T(m, T(n, k)) = T(T(m, n), k).
%F A344838 T(n, n) = n.
%F A344838 T(n, 0) = n.
%F A344838 T(n, 1) = max(1, n).
%e A344838 Array T(n, k) begins:
%e A344838 n\k| 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
%e A344838 ---+----------------------------------------------------------------
%e A344838 0| 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
%e A344838 1| 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
%e A344838 2| 2 2 2 3 4 5 6 7 8 9 10 11 12 13 14 15
%e A344838 3| 3 3 3 3 6 6 6 7 12 12 12 12 12 13 14 15
%e A344838 4| 4 4 4 6 4 5 6 7 8 9 10 11 12 13 14 15
%e A344838 5| 5 5 5 6 5 5 6 7 10 10 10 11 12 13 14 15
%e A344838 6| 6 6 6 6 6 6 6 7 12 12 12 12 12 13 14 15
%e A344838 7| 7 7 7 7 7 7 7 7 14 14 14 14 14 14 14 15
%e A344838 8| 8 8 8 12 8 10 12 14 8 9 10 11 12 13 14 15
%e A344838 9| 9 9 9 12 9 10 12 14 9 9 10 11 12 13 14 15
%e A344838 10| 10 10 10 12 10 10 12 14 10 10 10 11 12 13 14 15
%e A344838 11| 11 11 11 12 11 11 12 14 11 11 11 11 12 13 14 15
%e A344838 12| 12 12 12 12 12 12 12 14 12 12 12 12 12 13 14 15
%e A344838 13| 13 13 13 13 13 13 13 14 13 13 13 13 13 13 14 15
%e A344838 14| 14 14 14 14 14 14 14 14 14 14 14 14 14 14 14 15
%e A344838 15| 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15 15
%o A344838 (PARI) T(n,k,op=max,w=m->#binary(m)) = { op(n*2^max(0, w(k)-w(n)), k*2^max(0, w(n)-w(k))) }
%Y A344838 Cf. A003984, A070939.
%Y A344838 Cf. A344834 (AND), A344835 (OR), A344836 (XOR), A344837 (min), A344839 (absolute difference).
%K A344838 nonn,base,tabl
%O A344838 0,4
%A A344838 _Rémy Sigrist_, May 29 2021