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A007992 Augmented amicable pairs (smaller member of each pair). 3
6160, 12220, 23500, 68908, 249424, 425500, 434784, 649990, 660825, 1017856, 1077336, 1238380, 1252216, 1568260, 1754536, 2166136, 2362360, 2482536, 2537220, 2876445, 3957525, 4177524, 4287825, 5224660, 5559510, 5641552 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Let f(n) = 1 + sum of aliquot divisors of n; these are pairs (n,m) with f(n)=m, f(m)=n.

m cannot equal n. - Harvey P. Dale, May 18 2012

LINKS

Table of n, a(n) for n=1..26.

D. Moews, Augmented amicable pairs

J. O. M. Pedersen, Tables of Aliquot Cycles [Broken link]

J. O. M. Pedersen, Tables of Aliquot Cycles [Via Internet Archive Wayback-Machine]

J. O. M. Pedersen, Tables of Aliquot Cycles [Cached copy, pdf file only]

P. Pollack, Quasi-Amicable Numbers are Rare, J. Int. Seq. 14 (2011) # 11.5.2

MATHEMATICA

aapQ[n_]:=Module[{c=DivisorSigma[1, n]+1-n}, c!=n&&DivisorSigma[ 1, c]+1-c == n]; Transpose[Union[Sort[{#, DivisorSigma[1, #]+1-#}]&/@Select[Range[ 6000000], aapQ]]] [[1]] (* Harvey P. Dale, May 18 2012 *)

CROSSREFS

Cf. A015630.

Sequence in context: A204626 A318251 A281265 * A033288 A266586 A057880

Adjacent sequences:  A007989 A007990 A007991 * A007993 A007994 A007995

KEYWORD

nonn,nice

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified January 18 23:05 EST 2019. Contains 319282 sequences. (Running on oeis4.)