cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A094529 Numbers with at least one arithmetic progression of four divisors (not necessarily consecutive).

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%I A094529 #24 Mar 19 2016 13:08:17
%S A094529 12,24,36,48,60,72,84,96,105,108,120,132,140,144,156,168,180,192,204,
%T A094529 210,216,228,240,252,264,276,280,288,300,312,315,324,336,348,360,372,
%U A094529 384,396,408,420,432,440,444,456,468,480,492,504,516,525,528,540,552,560
%N A094529 Numbers with at least one arithmetic progression of four divisors (not necessarily consecutive).
%C A094529 All multiples of terms are also terms.
%C A094529 a(n) = m*A094530(k) for appropriate m and k.
%H A094529 Alois P. Heinz, <a href="/A094529/b094529.txt">Table of n, a(n) for n = 1..10000</a>
%t A094529 sd4Q[n_]:=Count[Subsets[Divisors[n],{4}],_?(Length[Union[ Differences[ #]]] == 1&)]>0; Select[Range[600],sd4Q] (* _Harvey P. Dale_, Mar 19 2016 *)
%Y A094529 Cf. A091011, A094530.
%Y A094529 See A270571 for another version.
%K A094529 nonn
%O A094529 1,1
%A A094529 _Reinhard Zumkeller_, May 07 2004
%E A094529 Edited by _Harvey P. Dale_ and _Alois P. Heinz_, Mar 18 2016