|
%I #2 Mar 30 2012 17:25:31
%S 1,2,2,3,3,6,4,4,8,8,5,5,10,10,20,6,6,12,12,24,12,7,7,14,14,28,14,42,
%T 8,8,16,16,32,16,48,32,9,9,18,18,36,18,54,36,54,10,10,20,20,40,20,60,
%U 40,60,40,11,11,22,22,44,22,66,44,66,44,110
%N Triangle read by rows, A127648 * A000012 * A130207, 1<=k<=n.
%C Row sums = A143270: (1, 4, 12, 24, 50, 72, 126, 176,...).
%F Triangle read by rows, A127648 * A000012 * A130207. T(n,k) = n*phi(k)
%e First few rows of the triangle =
%e 1;
%e 2, 2;
%e 3, 3, 6;
%e 4, 4, 8, 8;
%e 5, 5, 10, 10, 20;
%e 6, 6, 12, 12, 24, 12;
%e 7, 7, 14, 1428, 14, 42;
%e ...
%e Row 5 = (5, 5, 10, 10, 20) = (5*1, 5*1, 5*2, 5*2, 5*4); where phi(k) = (1, 1, 2, 2, 4,...).
%Y Cf. A000010, A143270.
%K nonn,tabl
%O 1,2
%A _Gary W. Adamson_, Aug 03 2008
|
