A306872 Lesser of augmented unitary amicable pair.
6224890, 37542190, 56523810, 101304490, 135657795, 233990890, 5304907426, 8473747030, 8483430670, 9220653310, 11033448910, 12139959910, 13108452735, 13849730895, 16697472870, 19644687195, 20321234206, 23076788295, 40575765615, 55636542346, 89094853155, 101786530846
Offset: 1
Keywords
Examples
6224890 is in the sequence since it is the lesser of the amicable pair (6224890, 7336455): usigma(6224890) = usigma(7336455) = 13561344 = 6224890 + 7336455 - 1.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..27 (terms below 10^12, from David Moews's site).
- David Moews, Perfect, amicable and sociable numbers
- J. O. M. Pedersen, Tables of Aliquot Cycles
Programs
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Mathematica
us[n_] := Times @@ (1 + Power @@@ FactorInteger[n]) - n; s={}; Do[m = us[n] + 1; If[m > n && us[m] == n - 1, AppendTo[s, n]], {n, 1, 10^9}]; s
Comments