The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A270571 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A270571

Numbers with at least one arithmetic progression of four consecutive divisors.
(history; published version)

#8 by Jon E. Schoenfield at Sun Feb 24 02:13:32 EST 2019

STATUS

editing

approved

#7 by Jon E. Schoenfield at Sun Feb 24 02:13:26 EST 2019

COMMENTS

Contrast A094529 where the divisors in arithmetic progression do not have to be consecutive.

CROSSREFS

Cf. A091011, A094529, A094530.

EXTENSIONS

Edited by _Harvey P. Dale _ and _Alois P. Heinz, _, Mar 19 2016

STATUS

approved

editing

#6 by Harvey P. Dale at Sat Mar 19 10:41:11 EDT 2016

STATUS

editing

approved

#5 by Harvey P. Dale at Sat Mar 19 10:41:04 EDT 2016

AUTHOR

_Reinhard Zumkeller, _, Mar 19 2016

EXTENSIONS

Edoted Edited by Harvey P. Dale and Alois P. Heinz, Mar 19 2016

STATUS

approved

editing

#4 by Harvey P. Dale at Sat Mar 19 10:39:55 EDT 2016

STATUS

editing

approved

#3 by Harvey P. Dale at Sat Mar 19 10:39:48 EDT 2016

LINKS

Harvey P. Dale, <a href="/A270571/b270571.txt">Table of n, a(n) for n = 1..1000</a>

EXTENSIONS

Edoted by Harvey P. Dale and Alois P. Heinz, Mar 19 2016

#2 by Harvey P. Dale at Sat Mar 19 10:37:26 EDT 2016

NAME

allocated for Harvey P. Dale

Numbers with at least one arithmetic progression of four consecutive divisors.

DATA

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

OFFSET

1,1

COMMENTS

Contrast A094529 where the divisors in arithmetic progression do not have be consecutive.

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

KEYWORD

allocated

nonn

AUTHOR

_Reinhard Zumkeller, Mar 19 2016

STATUS

approved

editing

#1 by Harvey P. Dale at Sat Mar 19 10:37:26 EDT 2016

NAME

allocated for Harvey P. Dale

KEYWORD

allocated

STATUS

approved