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A066539 Difference between larger and smaller terms of n-th amicable pair. 9
64, 26, 304, 544, 136, 112, 2310, 1120, 13064, 64, 4050, 18018, 8980, 23670, 17550, 784, 11512, 26420, 4480, 4576, 18064, 5720, 84544, 81304, 110852, 43184, 17888, 17150, 11680, 3510, 69296, 76144, 67072, 76592, 9328, 115592, 70592, 61110, 21712 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Values are sorted along increasing A002025. - R. J. Mathar, Jul 19 2009, Jul 23 2009

REFERENCES

For references see A002025.

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..415523

FORMULA

a(n) = A002046(n) - A002025(n).

a(n) = A259180(2n) - A259180(2n-1). - Omar E. Pol, Oct 22 2017

EXAMPLE

a(7) = 2310 because the 7th pair of amicable numbers is 12285 and 14595; and 14595 - 12285 = 2310.

MATHEMATICA

With[{s = PositionIndex@Array[DivisorSigma[1, #] &, 10^6]}, Flatten@ Map[Differences, Apply[Join, Map[Function[n, Select[Subsets[Lookup[s, n], {2}], Total@ # == n &]], Sort@ Select[Keys@ s, Length@ Lookup[s, #] > 1 &]]]]] (* Michael De Vlieger, Oct 22 2017 *)

CROSSREFS

Cf. A002025, A002046, A063990, A259180 (amicable pairs).

Sequence in context: A281721 A275469 A178542 * A095390 A033384 A073327

Adjacent sequences:  A066536 A066537 A066538 * A066540 A066541 A066542

KEYWORD

nonn

AUTHOR

Robert A. Stump (bee_ess107(AT)yahoo.com), Jan 06 2002

EXTENSIONS

Sorted on smaller term for alignment with A002046 and A002025. - R. J. Mathar, Jul 19 2009

A-number in comment corrected by R. J. Mathar, Jul 23 2009

STATUS

approved

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Last modified November 20 08:12 EST 2017. Contains 294962 sequences.