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A253587 The sum of the i-th ternary digits of n, k, and T(n,k) equals 0 (mod 3) for each i>=0 (leading zeros included); triangle T(n,k), n>=0, 0<=k<=n, read by rows.

%I A253587 #23 Oct 26 2018 09:15:54
%S A253587 0,2,1,1,0,2,6,8,7,3,8,7,6,5,4,7,6,8,4,3,5,3,5,4,0,2,1,6,5,4,3,2,1,0,
%T A253587 8,7,4,3,5,1,0,2,7,6,8,18,20,19,24,26,25,21,23,22,9,20,19,18,26,25,24,
%U A253587 23,22,21,11,10,19,18,20,25,24,26,22,21,23,10,9,11
%N A253587 The sum of the i-th ternary digits of n, k, and T(n,k) equals 0 (mod 3) for each i>=0 (leading zeros included); triangle T(n,k), n>=0, 0<=k<=n, read by rows.
%H A253587 Alois P. Heinz, <a href="/A253587/b253587.txt">Rows n = 0..200, flattened</a>
%H A253587 Wikipedia, <a href="https://en.wikipedia.org/wiki/Set_(game)">Set (game)</a>
%F A253587 T(n,k) = T(floor(n/3),floor(k/3))*3+(6-(n mod 3)-(k mod 3) mod 3), T(0,0) = 0.
%e A253587 Triangle T(n,k) begins:
%e A253587   0;
%e A253587   2, 1;
%e A253587   1, 0, 2;
%e A253587   6, 8, 7, 3;
%e A253587   8, 7, 6, 5, 4;
%e A253587   7, 6, 8, 4, 3, 5;
%e A253587   3, 5, 4, 0, 2, 1, 6;
%e A253587   5, 4, 3, 2, 1, 0, 8, 7;
%e A253587   4, 3, 5, 1, 0, 2, 7, 6, 8;
%p A253587 T:= proc(n, k) local i, j; `if`(n=0 and k=0, 0,
%p A253587       T(iquo(n, 3, 'i'), iquo(k, 3, 'j'))*3 +irem(6-i-j, 3))
%p A253587     end:
%p A253587 seq(seq(T(n, k), k=0..n), n=0..14);
%Y A253587 Column k=0 gives A004488.
%Y A253587 Main diagonal gives A001477.
%Y A253587 T(n,floor(n/3)) gives A060587.
%Y A253587 Cf. A090245, A253586.
%K A253587 nonn,base,tabl,look
%O A253587 0,2
%A A253587 _Alois P. Heinz_, Jan 04 2015