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%I #11 Apr 23 2017 01:01:13
%S 12,18,20,24,28,36,40,44,45,48,50,52,54,56,63,68,72,75,76,80,88,92,96,
%T 98,99,100,104,108,112,116,117,124,135,136,144,147,148,152,153,160,
%U 162,164,171,172,175,176,184,188,189,192,196,200,207,208,212,216,224,225
%N Indices n such that A123709(n) = 8 = number of nonzero terms in row n of triangle A123706.
%C Triangle A123706 is the matrix inverse of triangle A010766, where A010766(n,k) = [n/k].
%C It appears that this equals A200511, numbers of the form p^k q^m with k,m >= 1, k+m > 2 and p, q prime. - _M. F. Hasler_, Feb 12 2012
%H G. C. Greubel, <a href="/A123711/b123711.txt">Table of n, a(n) for n = 1..1000</a>
%t Moebius[i_, j_] := If[Divisible[i, j], MoebiusMu[i/j], 0]; A123709[n_] :=
%t Length[Select[Table[Moebius[n, j] - Moebius[n, j + 1], {j, 1, n}], # != 0 &]]; Select[Range[500], A123709[#] == 8 &] (* _G. C. Greubel_, Apr 22 2017 *)
%o (PARI)
%Y Cf. A123706, A123709, A123710, A123712; A010766.
%K nonn
%O 1,1
%A _Paul D. Hanna_, Oct 09 2006
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