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%I
%S 0,0,2,0,2,0,4,4,4,0,2,0,4,4,4,0,2,0,4,4,4,0,6,6,6,6,6,0,2,0,6,6,6,6,
%T 6,0,4,4,4,0,2,0,4,4,4,0,6,6,6,6,6,0,6,6,6,6,6,0,2,0,6,6,6,6,6,0,4,4,
%U 4,0,2,0,6,6,6,6,6,0,4,4,4,0,6,6,6,6,6,0,8,8,8,8,8,8,8,0,4,4,4,0,2,0,4,4,4
%N Difference between (least prime >= n) and (largest prime <= n).
%C a(n)=0 iff n is prime.
%F a(n) = A057427(n - A007917(n)) * A001223(A049084(A007917(n))).
%t f[n_]:=If[PrimeQ[n],0,NextPrime[n]-NextPrime[n,-1]];Array[f,110,2] (* From Harvey P. Dale, Sep 22 2011 *)
%o (Mupad) numlib::prevprime(i)*(-1)-nextprime(i)*(-1)$ i = 2..106 - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Feb 26 2007
%Y a(n) = A007918(n) - A007917(n).
%Y Cf. A072681, A013633.
%K nonn
%O 2,3
%A _Reinhard Zumkeller_, Jul 01 2002
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