A324367 - OEIS

A324367

Numbers k such that s(k) = s(k+1) where s(k) is the sum of divisors of k that are larger than sqrt(k) (A238535).

45, 62, 15795, 355022, 14257705, 28856174, 2324581982, 103321586193

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

a(9) > 2*10^11. - Giovanni Resta, Sep 06 2019

LINKS

EXAMPLE

45 is in the sequence since A238535(45) = A238535(46) = 69.

MATHEMATICA

s[n_] := DivisorSum[n, # &, # > Sqrt[n] &]; seq={}; s1 = 0; Do[s2 = s[n]; If[s1 == s2, AppendTo[seq, n - 1]]; s1 = s2, {n, 2, 10000}]; seq

CROSSREFS

KEYWORD

nonn,more

AUTHOR

Amiram Eldar, Sep 03 2019

EXTENSIONS

a(8) from Giovanni Resta, Sep 06 2019

STATUS

approved