cp's OEIS Frontend

A210700 A047160(3n): smallest m >= 0 with both 3n - m and 3n + m prime.

%I A210700 #16 Sep 23 2022 14:07:04
%S A210700 0,1,2,1,2,1,2,5,4,1,4,5,2,1,2,5,8,7,4,1,4,5,2,1,4,5,2,5,14,7,4,7,2,1,
%T A210700 2,1,2,13,10,7,14,13,2,5,4,1,10,5,10,1,4,7,8,5,2,5,8,7,4,1,10,5,8,1,2,
%U A210700 1,10,7,16,13,14,17,8,11,2,1,2,5,4,1,14,5
%N A210700 A047160(3n): smallest m >= 0 with both 3n - m and 3n + m prime.
%C A210700 This sequence is interesting because, apart from a(2)=1, A155764 appears to consist only of multiples of three. Equivalently, since n and A047160(n) are coprime (for nonzero A047160(n)), no multiple of three appears to occur in A155765.
%H A210700 Jason Kimberley, <a href="/A210700/b210700.txt">Table of n, a(n) for n = 1..3333</a>
%H A210700 OEIS (Plot 2), <a href="/plot2a?name1=A27&amp;name2=A210700&amp;tform1=log+base+10&amp;tform2=log+base+10&amp;shift=0&amp;radiop1=xy&amp;drawpoints=true">Plot of (log(n), log(a(n)))</a>
%H A210700 OEIS (Plot 2), <a href="/plot2a?name1=A210701&amp;name2=A210702&amp;tform1=log+base+10&amp;tform2=log+base+10&amp;shift=0&amp;radiop1=xy&amp;drawpoints=true">Plot of (log(A210701(n)), log(A210702(n)))</a>
%t A210700 sml[n_]:=Module[{m=0},While[!PrimeQ[3n-m]||!PrimeQ[3n+m],m++];m]; Array[ sml,100] (* _Harvey P. Dale_, Sep 23 2022 *)
%Y A210700 Cf. A210701 (location of records in this sequence), A210702 (records in this sequence).
%K A210700 nonn,easy
%O A210700 1,3
%A A210700 _Jason Kimberley_, Oct 15 2012