cp's OEIS Frontend

A114233 Smallest number m such that 2*prime(n) + prime(m) is a prime.

%I A114233 #8 Sep 30 2017 18:14:28
%S A114233 2,2,4,2,2,2,4,2,3,3,4,2,2,2,6,3,2,4,2,3,4,2,2,11,3,6,3,2,2,4,2,2,6,3,
%T A114233 2,3,2,2,11,3,4,2,2,2,5,2,2,2,6,6,3,4,4,11,2,3,2,4,2,4,2,8,3,4,5,2,4,
%U A114233 2,2,14,3,3,2,2,8,2,4,2,8,5,8,5,2,14,6,3,4,2,2,6,2,11,5,2,2,4,2,3,2,2,2,6,5
%N A114233 Smallest number m such that 2*prime(n) + prime(m) is a prime.
%H A114233 Reinhard Zumkeller, <a href="/A114233/b114233.txt">Table of n, a(n) for n = 3..10000</a>
%e A114233 n=3: 2*prime(3)+prime(2)=2*5+3=13 is prime, so a(3)=2;
%e A114233 n=4: 2*prime(4)+prime(2)=2*7+3=17 is prime, so a(4)=2;
%e A114233 n=5: 2*prime(5)+prime(2)=2*11+3=25 is not prime
%e A114233 ...
%e A114233 2*prime(5)+prime(4)=2*11+7=29 is prime, so a(5)=4.
%t A114233 Table[p1 = Prime[n1]; n2 = 1; p2 = Prime[n2]; While[cp = 2*p1 + p2; ! PrimeQ[cp], n2++; If[n2 >= n1, Print[n1]]; p2 = Prime[n2]]; n2, { n1, 3, 202}]
%t A114233 snm[n_]:=Module[{m=1,p=2Prime[n]},While[!PrimeQ[p+Prime[m]],m++];m]; Array[ snm,110,3] (* _Harvey P. Dale_, Sep 30 2017 *)
%o A114233 (Haskell)
%o A114233 a114233 n = head [m | m <- [1 .. n],
%o A114233                       a010051' (2 * a000040 n + a000040 m) == 1]
%o A114233 -- _Reinhard Zumkeller_, Oct 31 2013
%Y A114233 Cf. A073703, A114227, A114228, A114231.
%Y A114233 Cf. A010051, A000040.
%K A114233 easy,nonn
%O A114233 3,1
%A A114233 _Lei Zhou_, Nov 20 2005
%E A114233 Edited definition to conform to OEIS style. - _Reinhard Zumkeller_, Oct 31 2013