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.

A307963 Larger of coreful amicable numbers pair: numbers (m, n) such that csigma(m) = csigma(n) = m + n, where csigma(n) is the sum of the coreful divisors of n (A057723).

Original entry on oeis.org

2218040, 4924700, 6654120, 15526280, 14774100, 28834520, 37706680, 42142760, 34472900, 46578840, 51014920, 64323160, 68759240, 64021100, 82067480, 86503560, 90939640, 95375720, 104247880, 83719900, 113120040, 117556120, 93569300, 126428280, 103418700, 130864360
Offset: 1

Views

Author

Amiram Eldar, May 08 2019

Keywords

Comments

The terms are ordered according to the their lesser counterparts (A307962).

Crossrefs

Programs

  • Mathematica
    f[p_,e_] := (p^(e+1)-1)/(p-1)-1; csigma[1]=1; csigma[n_] := Times @@ (f @@@ FactorInteger[n]); s={}; Do[m = csigma[n] - n; If[m > n && csigma[m] - m == n, AppendTo[s, m]], {n, 1, 10^8}]; s