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Smallest m such that prime(n) mod m > 1.
1

%I #5 Aug 04 2021 11:58:08

%S 3,4,3,4,3,5,3,4,3,3,4,5,3,4,3,3,3,7,4,3,5,4,3,3,5,3,4,3,5,3,4,3,3,4,

%T 3,4,5,4,3,3,3,7,3,5,3,4,4,4,3,5,3,3,7,3,3,3,3,4,5,3,4,3,4,3,5,3,4,5,

%U 3,5,3,3,4,5,4,3,3,5,3,5,3,8,3,5,4,3,3,5,3,4,3,3,4,3,4,3,3,3,4,7,4,3

%N Smallest m such that prime(n) mod m > 1.

%e A000040(25)=97: 97 mod 1 = 0, 97 mod 2 = 1, 97 mod 3 = 1, 97

%e mod 4 = 1, but 97 mod 5 = 2>1, therefore a(25)=5.

%t smp1[n_]:=Module[{m=2},While[Mod[n,m]<2,m++];m]; smp1/@Prime[Range[120]] (* _Harvey P. Dale_, Aug 04 2021 *)

%K nonn

%O 1,1

%A _Reinhard Zumkeller_, Jul 12 2004