cp's OEIS Frontend

A114234 n(k) is the minimum n that requires at least k to make 2*Prime[n]+Prime[k] a prime.

%I A114234 #3 Mar 31 2012 10:23:47
%S A114234 3,11,5,47,17,106,64,157,133,26,236,308,72,496,122,207,152,142,197,
%T A114234 259,514,497,1266,1482,2005,2193,1380,964,3662,534,4055,667,2513,6083,
%U A114234 1794,689,3332,5771,3713,4587,3450,12520,5712,3242,10252,18663,11912,25124
%N A114234 n(k) is the minimum n that requires at least k to make 2*Prime[n]+Prime[k] a prime.
%C A114234 Shows the first 204 items; The first appearance in A114233; Sequence is defined for all k>=2.
%e A114234 k=2: 2*Prime[3]+Prime[2]=13 is prime, so n(2)=3;
%e A114234 2*Prime[4]+Prime[2]=17
%e A114234 2*Prime[5]+Prime[2]=25, ... 2*Prime[5]+Prime[4]=29 ==> n(4)=5;
%t A114234 Do[n[k] = 0, {k, 2, 2000}]; ct = 0; nm = 0; n2 = 0; n1 = 3; p1 = 5; While[ct < 200, n2 = 1; p2 = Prime[n2]; While[cp = 2*p1 + p2; ! PrimeQ[cp], n2++; p2 = Prime[n2]]; If[n[n2] == 0, n[ n2] = n1; If[n2 > nm, nm = n2]; If[n2 <= 201, ct++ ]; Print[Table[n[k], {k, 2, nm}]]]; n1++; p1 = Prime[n1]];
%Y A114234 Cf. A073703, A114227, A114229, A114232, A114233.
%K A114234 nonn
%O A114234 2,1
%A A114234 _Lei Zhou_, Nov 20 2005