login
Numbers k such that s(k) = s(k+1), where s(k) is the sum of unitary divisors of k that are larger than sqrt(k) (A334023).
0

%I #4 Apr 12 2020 21:44:15

%S 24752,101972,14257705

%N Numbers k such that s(k) = s(k+1), where s(k) is the sum of unitary divisors of k that are larger than sqrt(k) (A334023).

%C a(4) > 10^10.

%e 24752 is a term since A334023(24752) = A334023(24753) = 33896.

%t s[n_] := DivisorSum[n, # &, #^2 > n && CoprimeQ[#, n/#] &]; Select[Range[1.5*10^7], s[#] == s[# + 1] &]

%Y Cf. A064125, A324367, A334020, A334023.

%K nonn,bref,more

%O 1,1

%A _Amiram Eldar_, Apr 12 2020