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%I #13 Mar 29 2020 14:58:04
%S 0,0,2,1,0,0,0,7,7,8,9,9,9,10,10,10,10,10,11,12,12,12,12,12,13,13,13,
%T 14,15,15,15,16,16,16,16,16,17,17,17,17,17,18,19,19,19,19,19,20,20,20,
%U 21,22,22,22,22,22,23,23,23,24,24,24,24,24,25,25,25,25,25,25,25,26,26
%N Remainder when the n-th composite number is divided by n.
%H Harry J. Smith, <a href="/A065860/b065860.txt">Table of n, a(n) for n = 1..1000</a>
%F a(n) = A002808(n) mod n.
%e n=100, c(100)=133, a(100)=33.
%t Module[{nn=100,cmps,len},cmps=Select[Range[nn],CompositeQ];len=Length[ cmps]; Mod[#[[1]],#[[2]]]&/@Thread[{cmps,Range[len]}]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Mar 29 2020 *)
%o (PARI) Composite(n) = { local(k); k=n + primepi(n) + 1; while (k != n + primepi(k) + 1, k = n + primepi(k) + 1); return(k) } { for (n = 1, 1000, a=Composite(n)%n; write("b065860.txt", n, " ", a) ) } \\ _Harry J. Smith_, Nov 02 2009
%Y Cf. A002808, A065855-A065864.
%K nonn
%O 1,3
%A _Labos Elemer_, Nov 26 2001
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