%I #11 May 21 2017 14:32:38

%S 1,1,0,-1,0,0,1,2,3,0,0,0,2,2,-2,-1,0,2,2,-2,-1,0,1,-2,3,4,-2,-2,0,-4,

%T 2,-2,-2,0,0,-3,2,4,-2,2,0,-2,4,0,-2,2,1,-6,3,2,0,-2,2,-4,-2,-1,-2,0,

%U 0,0,4,4,-2,-5,0,-4,2,-2,-2,0,0,0,4,4,-1,-2,1,-4,3,2,-1,0,2,0,-2,8,0,4,2,-4,0,0,-2,2,2,0,4,2,2,-7,0,0,6,2,-6,4,0,4,2

%N a(n) = d(n+d(n)) - d(n), where d(n) is the number of divisors of n (A000005).

%H Antti Karttunen, <a href="/A286530/b286530.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A286529(n) - A000005(n) = A000005(n+A000005(n)) - A000005(n).

%t Table[DivisorSigma[0, n + DivisorSigma[0, n]] - DivisorSigma[0, n], {n, 109}] (* _Michael De Vlieger_, May 21 2017 *)

%o (PARI) A286530(n) = (numdiv(n+numdiv(n)) - numdiv(n));

%o (Scheme) (define (A286530 n) (- (A286529 n) (A000005 n)))

%o (Python)

%o from sympy import divisor_count as d

%o def a(n): return d(n + d(n)) - d(n) # _Indranil Ghosh_, May 21 2017

%Y Cf. A000005, A286529, A286480.

%Y Cf. A175304 (the positions of zeros).

%K sign

%O 1,8

%A _Antti Karttunen_, May 21 2017