cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A126166 Larger member of each exponential amicable pair.

Original entry on oeis.org

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

Views

Author

Ant King, Dec 21 2006

Keywords

Comments

This sequence includes the largest member of all exponential amicable pairs and does not discriminate between primitive and nonprimitive pairs.

Examples

			a(3)= 968436 because (937692,968436) is the third exponential amicable pair
		

References

  • Hagis, Peter Jr.; Some Results Concerning Exponential Divisors, Internat. J. Math. & Math. Sci., Vol. 11, No. 2, (1988), pp. 343-350.

Crossrefs

Programs

  • 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 *)

Formula

The values of n for which esigma(m)=esigma(n)=m+n and mA051377

Extensions

Link corrected and reference added by Andrew Lelechenko, Dec 04 2011
More terms from Amiram Eldar, May 09 2019