%I
%S 1,2,3,3,6,1,4,9,2,3,5,12,3,6,1,6,15,4,9,2,3,7,18,5,12,3,6,1,8,21,6,
%T 15,4,9,2,3,9,24,7,18,5,12,3,6,1,10,27,8,21,6,15,4,9,2,3,11,30,9,24,7,
%U 18,5,12,3,6,1,12,33,10,27,8,21,6,15,4,9,2,3,13,36,11,30,9,24,7,18,5,12,3,6
%N Triangle read by rows: T(i,j) is the (i,j)entry (1 <= j <= i) of the product R*Q of the infinite lower triangular matrices R = [1; 1,1; 1,1,1; 1,1,1,1;...] and Q = [1; 1,3; 1,3,1; 1 3,1,3; ...].
%F Even columns (offset) = 1, 2, 3, ...; while odd columns = 3, 6, 9, ...
%F T(i,j) = ij+1 if j <= i and j is odd; 3(ij+1) if j <= i and j is even.  _Emeric Deutsch_, Mar 23 2005
%e The first few rows of the triangle are:
%e 1;
%e 2, 3;
%e 3, 6, 1;
%e 4, 9, 2, 3;
%e ...
%p T:=proc(i,j) if j>i then 0 elif j mod 2 = 1 then ij+1 else 3*(ij+1) fi end:for i from 1 to 14 do seq(T(i,j),j=1..i) od; # yields sequence in triangular form # _Emeric Deutsch_, Mar 23 2005
%Y Cf. A035608, A074377, A104569.
%Y Row sums yield A035608. The product Q*R yields A104569.
%K nonn,tabl
%O 1,2
%A _Gary W. Adamson_, Mar 16 2005
%E More terms from _Emeric Deutsch_, Mar 23 2005
