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

Offset

1,1

Comments

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

Links

Table of n, a(n) for n=1..8.

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

Cf. A002961, A064115, A064125, A164522, A164557, A238535, A293183, A306985, A324295.

Sequence in context: A348922 A179007 A138046 * A140276 A140277 A242263

Adjacent sequences: A324364 A324365 A324366 * A324368 A324369 A324370

Keyword

nonn,more

Author

Amiram Eldar, Sep 03 2019

Extensions

a(8) from Giovanni Resta, Sep 06 2019

Status

approved