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A094529 Numbers with at least one arithmetic progression of four divisors (not necessarily consecutive). 3
12, 24, 36, 48, 60, 72, 84, 96, 105, 108, 120, 132, 140, 144, 156, 168, 180, 192, 204, 210, 216, 228, 240, 252, 264, 276, 280, 288, 300, 312, 315, 324, 336, 348, 360, 372, 384, 396, 408, 420, 432, 440, 444, 456, 468, 480, 492, 504, 516, 525, 528, 540, 552, 560 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All multiples of terms are also terms.

a(n) = m*A094530(k) for appropriate m and k.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..10000

MATHEMATICA

sd4Q[n_]:=Count[Subsets[Divisors[n], {4}], _?(Length[Union[ Differences[ #]]] == 1&)]>0; Select[Range[600], sd4Q] (* Harvey P. Dale, Mar 19 2016 *)

CROSSREFS

Cf. A091011, A094530.

See A270571 for another version.

Sequence in context: A336657 A066085 A340511 * A270571 A044852 A121578

Adjacent sequences:  A094526 A094527 A094528 * A094530 A094531 A094532

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, May 07 2004

EXTENSIONS

Edited by Harvey P. Dale and Alois P. Heinz, Mar 18 2016

STATUS

approved

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Last modified August 11 08:17 EDT 2022. Contains 356055 sequences. (Running on oeis4.)