OFFSET
1,4
COMMENTS
For more information see A237270.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..5000 (computed from the b-file of A237271 provided by Michel Marcus)
EXAMPLE
For n = 9 the divisors of 9 are [1, 3, 9] and the parts of the symmetric representation of sigma(9) are [5, 3, 5]. In both cases there are three elements, so a(9) = 3 - 3 = 0.
For n = 10 the four divisors of 10 are [1, 2, 5, 10] and the two parts of the symmetric representation of sigma(10) are [9, 9], so a(10) = 4 - 2 = 2.
MATHEMATICA
(* Function a237270[] is defined in A237270 *)
a243982[n_]:=Length[Divisors[n] - Length[a237270[n]]
a243982[m_, n_]:=Map[a243982, Range[m, n]]
a243982[1, 104]] (* data *)
(* Hartmut F. W. Hoft, Sep 19 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Jun 16 2014
EXTENSIONS
a(94)-a(95) corrected by Omar E. Pol, Jul 02 2014
STATUS
approved