Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #11 May 29 2023 13:19:48
%S 1,2,0,2,1,0,3,0,1,0,2,1,1,1,0,4,1,0,0,1,0,2,1,1,1,1,1,0,4,0,2,0,1,0,
%T 1,0,3,2,0,1,1,0,1,1,0,4,1,2,1,0,0,1,0,1,0,2,1,1,1,1,1,1,1,1,1,0,6,1,
%U 1,0,2,0,1,0,0,0,1,0
%N Triangle read by rows: A051731 * A054521, as infinite lower triangular matrices.
%C Row sums = n, left column = d(n), (A000005: 1, 2, 2, 3, 2, 4, 2, ...).
%F Inverse Moebius transform of A054521.
%e First few rows of the triangle:
%e 1;
%e 2, 0;
%e 2, 1, 0;
%e 3, 0, 1, 0;
%e 2, 1, 1, 1, 0;
%e 4, 1, 0, 0, 1, 0;
%e 2, 1, 1, 1, 1, 1, 0;
%e 4, 0, 2, 0, 1, 0, 1, 0;
%e 3, 2, 0, 1, 1, 0, 1, 1, 0;
%e ...
%Y Cf. A000005, A051731, A054521.
%K nonn,tabl
%O 1,2
%A _Gary W. Adamson_, Jan 12 2007
%E Definition clarified, a(56) corrected and more terms from _Georg Fischer_, May 29 2023