OFFSET
1,1
COMMENTS
The sum of unitary divisors of numbers n such that n and n+1 have the same sum.
The unitary version of A053215.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
usigma[n_] := Block[{d = Divisors[n]}, Plus @@ Select[d, GCD[ #, n/# ] == 1 &]]; a={}; u1=0; For[k=0, k<10^5, k++; u2=usigma[k]; If[u1==u2, a = AppendTo[a, u1]]; u1=u2]; a
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Jul 26 2017
STATUS
approved