A007992 Augmented amicable pairs (smaller member of each pair).

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

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

Amiram Eldar, Table of n, a(n) for n = 1..1159

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