A159905 - OEIS

%I #2 Mar 30 2012 17:25:34

%S 1,1,1,2,2,1,2,2,2,1,4,4,3,2,1,2,2,3,3,2,1,6,6,5,4,3,2,1,4,4,4,4,4,3,

%T 2,1,6,6,6,6,5,4,3,2,1,4,4,5,5,5,5,4,3,2,1,10,10,9,8,7,6,5,4,3,2,1,4,

%U 4,4,5,6,6,6,5,4,3,2,1

%N Triangle read by rows, Mobius transform of A004736

%C Row sums = A007438, Mobius transform of the triangular numbers.

%C Left border = phi(n), A000010.

%F Triangle read by rows, A054525 * A004736. A054525 = the Mobius transform, A004736 = the natural number "decrescendo" triangle: (1; 2,1; 3,2,1;...)

%e First few rows of the triangle =

%e 1;

%e 1, 1;

%e 2, 2, 1;

%e 2, 2, 2, 1;

%e 4, 4, 3, 2, 1;

%e 2, 2, 3, 3, 2, 1;

%e 6, 6, 5, 4, 3, 2, 1;

%e 4, 4, 4, 4, 4, 3, 2, 1;

%e 6, 6, 6, 6, 5, 4, 3, 2, 1;

%e 4, 4, 5, 5, 5, 5, 4, 3, 2, 1;

%e ...

%Y Cf. A007438

%K nonn,tabl

%O 1,4

%A _Gary W. Adamson_, Apr 25 2009