login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A126166
Larger member of each exponential amicable pair.
13
100548, 502740, 968436, 1106028, 1307124, 1709316, 2312604, 2915892, 3116988, 3720276, 4122468, 4323564, 4725756, 5027400, 4842180, 5329044, 5530140, 5932332, 6133428, 6535620, 6736716, 7138908, 7340004, 7943292, 8345484, 8546580, 8948772, 9753156, 10155348
OFFSET
1,1
COMMENTS
This sequence includes the largest member of all exponential amicable pairs and does not discriminate between primitive and nonprimitive pairs.
REFERENCES
Hagis, Peter Jr.; Some Results Concerning Exponential Divisors, Internat. J. Math. & Math. Sci., Vol. 11, No. 2, (1988), pp. 343-350.
LINKS
Peter Hagis, Jr., Some results concerning exponential divisors, International Journal of Mathematics and Mathematical Sciences, Vol. 11, No. 2, (1988), pp. 343-349.
FORMULA
The values of n for which esigma(m)=esigma(n)=m+n and m<n, where esigma is defined in A051377
EXAMPLE
a(3)= 968436 because (937692,968436) is the third exponential amicable pair
MATHEMATICA
fun[p_, e_] := DivisorSum[e, p^# &]; esigma[1] = 1; esigma[n_] := Times @@ fun @@@ FactorInteger[n]; s = {}; Do[m = esigma[n] - n; If[m > n && esigma[m] - m == n, AppendTo[s, m]], {n, 1, 10^7}]; s (* Amiram Eldar, May 09 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Ant King, Dec 21 2006
EXTENSIONS
Link corrected and reference added by Andrew Lelechenko, Dec 04 2011
More terms from Amiram Eldar, May 09 2019
STATUS
approved