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%I #10 Nov 23 2017 20:18:16
%S 1,1,2,1,1,1,3,3,1,1,2,1,1,1,2,1,2,1,2,1,1,1,3,5,1,3,2,1,1,1,2,1,1,1,
%T 2,1,1,1,2,1,1,1,3,3,1,1,4,5,2,1,2,1,2,1,2,1,1,1,2,1,1,3,2,1,1,1,2,1,
%U 1,1,2,1,1,3,2,1,1,1,3,3,1,1,2,1,1,1,2,1,2,1,2,1,1,1,2,1,4,3,2,1,1,1,2,1,1
%N Least k such that n+k is squarefree and coprime to n.
%C a(n) = A079114(n) - n.
%H Antti Karttunen, <a href="/A079115/b079115.txt">Table of n, a(n) for n = 1..16384</a>
%e From _Michael De Vlieger_, Nov 23 2017: (Start)
%e First positions of values in a(n):
%e n a(n)
%e --------------
%e 1 1
%e 3 2
%e 7 3
%e 47 4
%e 24 5
%e 1679 6
%e 120 7
%e 843 8
%e 2522 9
%e 72471 10
%e 840 11
%e 64050 13
%e 1674274 15
%e 404580 17
%e 2042040 19
%e (End)
%t Table[Block[{k = 1}, While[Nand[SquareFreeQ[n + k], CoprimeQ[n, n + k]], k++]; k], {n, 105}] (* _Michael De Vlieger_, Nov 23 2017 *)
%o (PARI) A079115(n) = { my(k=1); while((!issquarefree(n+k))||(gcd(n,n+k)>1), k++); k; } \\ _Antti Karttunen_, Nov 23 2017
%Y Cf. A005117, A079114.
%K nonn
%O 1,3
%A _Reinhard Zumkeller_, Dec 25 2002