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A007992
Augmented amicable pairs (smaller member of each pair).
8
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
The term "augmented amicable numbers" was coined by Beck and Wajar (1977), who found the first 11 pairs. They also found the next 25 pairs (1993). - Amiram Eldar, Mar 09 2024
LINKS
Walter E. Beck and Rudolph M. Wajar, More reduced amicable pairs, Fibonacci Quarterly, Vol. 15, No. 4 (1977), pp. 331-332.
Walter E. Beck and Rudolph M. Wajar, Reduced and Augmented Amicable Pairs to 10^8, Fibonacci Quarterly, Vol. 31, No. 4 (1993), pp. 295-298.
J. O. M. Pedersen, Tables of Aliquot Cycles.
J. O. M. Pedersen, Tables of Aliquot Cycles. [Cached copy, pdf file only]
Paul Pollack, Quasi-Amicable Numbers are Rare, J. Int. Seq. 14 (2011), Article 11.5.2.
Eric Weisstein's World of Mathematics, Augmented Amicable Pair.
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
KEYWORD
nonn,nice
STATUS
approved