login
A131907
Integers for which a smaller positive integer exists which has the same sum of cubes of its divisors.
3
194315, 295301, 2953010, 1181204, 1476505, 1886920, 2067107, 2362408, 2526095, 2953010, 3248311, 3691985, 3838913, 4134214, 4469245, 4724816, 5020117, 5610719, 5635135, 5906020, 6023765, 6496622, 6791923, 7382525, 7677826
OFFSET
1,1
COMMENTS
If i < j and A001158(i) = A001158(j) then j is in this sequence. - Jason Yuen, Sep 22 2024
FORMULA
n-th element of {x>0: there exists a k with 0<k<x and the same sum of the cubes of its divisors as x}.
EXAMPLE
194315 is in this sequence because A001158(184926) = A001158(194315) = 7401260364550416.
MATHEMATICA
First@Transpose[Reap[For[n = 1, n <= 5*10^6, n++, (If[Head[ #1] === tmp, #1 = n, Sow[{n, #1}]] & )[ tmp[DivisorSigma[3, n]]]]][[2, 1]]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Pein (petsie(AT)dordos.net), Jul 26 2007, Jul 28 2007
EXTENSIONS
More terms from Max Alekseyev and Daniel Lichtblau (danl(AT)wolfram.com), Jul 28 2007
STATUS
approved