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 A270571 Numbers with at least one arithmetic progression of four consecutive divisors. 2
 12, 24, 36, 48, 60, 72, 84, 96, 105, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, 240, 252, 264, 276, 288, 300, 312, 315, 324, 336, 348, 360, 372, 384, 396, 408, 420, 432, 444, 456, 468, 480, 492, 504, 516, 525, 528, 540, 552, 564, 576, 588, 600 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Contrast A094529 where the divisors in arithmetic progression do not have to be consecutive. LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 EXAMPLE 348 is included because its divisors are 1, 2, 3, 4, 6, 12, 29, 58, 87, 116, 174, and 348, and the first four are in arithmetic progression. MATHEMATICA ap4dQ[n_]:=Count[Partition[Divisors[n], 4, 1], _?(Length[ Union[ Differences[ #]]] == 1&)]>0; Select[ Range[700], ap4dQ] CROSSREFS Cf. A091011, A094529, A094530. Sequence in context: A066085 A340511 A094529 * A044852 A121578 A044897 Adjacent sequences:  A270568 A270569 A270570 * A270572 A270573 A270574 KEYWORD nonn AUTHOR Reinhard Zumkeller, Mar 19 2016 EXTENSIONS Edited by Harvey P. Dale and Alois P. Heinz, Mar 19 2016 STATUS approved

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Last modified August 10 03:07 EDT 2022. Contains 356029 sequences. (Running on oeis4.)