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a(n) = smallest number m >=0 such that n*prime(n)-m is a prime.
1

%I #5 Nov 21 2013 12:48:41

%S 0,1,2,5,2,5,6,1,8,7,4,1,10,1,4,9,6,1,14,11,2,5,2,5,2,5,4,25,24,1,6,

%T 15,2,3,6,5,2,21,22,3,6,11,4,25,2,3,10,13,4,3,16,7,10,1,28,5,2,35,4,

%U 17,6,17,8,13,4,1,6,9,14,9,6,1,8,19,14,7,6,17,12,1,2,3,2,19,2,15,16,3,6,1,6

%N a(n) = smallest number m >=0 such that n*prime(n)-m is a prime.

%t f[n_]:=Module[{pn=n Prime[n]},pn-NextPrime[pn,-1]]; Join[{0}, Array[f,100,2]] (* _Harvey P. Dale_, Jul 21 2011 *)

%Y Cf. A107061.

%K nonn

%O 1,3

%A _Zak Seidov_, May 10 2005