cp's OEIS Frontend

A114236 Smallest number m such that 2*prime(n)+prime(n-m) is a prime.

%I A114236 #6 Oct 31 2013 17:42:59
%S A114236 1,1,1,1,1,5,3,4,4,2,2,1,1,2,6,1,2,8,5,2,2,2,1,4,1,1,5,11,1,1,2,2,8,3,
%T A114236 2,5,2,2,3,1,1,1,1,5,2,3,1,10,4,4,4,1,5,12,9,1,2,1,5,3,1,1,1,1,12,2,1,
%U A114236 6,6,5,1,5,3,8,3,6,4,4,6,5,1,1,4,2,5,11,4,11,6,12,1,6,1,3,7,10,1,9,5,3,3,9
%N A114236 Smallest number m such that 2*prime(n)+prime(n-m) is a prime.
%H A114236 Reinhard Zumkeller, <a href="/A114236/b114236.txt">Table of n, a(n) for n = 3..10000</a>
%e A114236 n=3: 2*prime(3)+prime(3-1)=2*5+3=13 is prime, so a(3)=1;
%e A114236 n=4: 2*prime(4)+prime(4-1)=2*7+5=19 is prime, so a(4)=1;
%e A114236 ...
%e A114236 n=8: 2*prime(8)+prime(8-5)=2*19+5=43 is prime, so a(8)=5;
%t A114236 Table[p1 = Prime[n1]; n2 = 1; p2 = Prime[n1 - n2]; While[cp = 2*p1 + p2; ! PrimeQ[cp], n2++; If[n2 >= n1, Print[n1]]; p2 = Prime[n1 - n2]]; n2, {n1, 3, 202}]
%o A114236 (Haskell)
%o A114236 a114236 n = head [m | m <- [1..],
%o A114236                       a010051 (2 * a000040 n + a000040 (n - m)) == 1]
%o A114236 -- _Reinhard Zumkeller_, Oct 31 2013
%Y A114236 Cf. A114227, A114230, A073703, A114228, A114231, A114233, A114235.
%Y A114236 Cf. A010051, A000040.
%K A114236 easy,nonn
%O A114236 3,6
%A A114236 _Lei Zhou_, Nov 20 2005
%E A114236 Edited definition to conform to OEIS style. - _Reinhard Zumkeller_, Oct 31 2013