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URL: https://oeis.org/A063714

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A063714
Values of r occurring in A063713.
2
3, 3, 5, 3, 3, 5, 3, 19, 5, 3, 7, 29, 3, 5, 3, 5, 3, 43, 5, 3, 7, 3, 7, 3, 5, 3, 11, 3, 5, 5, 3, 7, 89, 7, 3, 5, 3, 3, 5, 3, 13, 113, 7, 13, 127, 5, 3, 11, 137, 139, 5, 13, 3, 7, 3, 5, 5, 3, 7, 3, 13, 5, 19, 3, 3, 31, 197, 199, 7, 13, 17, 11, 3, 5, 3, 229, 5, 3, 11, 5, 11, 3, 19, 3, 7, 3, 7
OFFSET
1,1
COMMENTS
This is not a mere union of A002373 and A020483 because of the minimality property of these sequences.
LINKS
MAPLE
f:= proc(n) local k;
k:= 2;
while k < 2*n do
k:= nextprime(k);
if isprime(2*n+k) and isprime(2*n-k) then return k fi
od;
NULL
end proc:
map(f, [$1..400]); # Robert Israel, Oct 09 2017
MATHEMATICA
f[n_] := {AnyTrue[Prime[Range[PrimePi[2n-2]]], (r = #; PrimeQ[2n+r] && PrimeQ[2n-r])&], r}; Select[f /@ Range[200], #[[1]] =!= False &][[All, 2]] (* Jean-François Alcover, Feb 14 2018 *)
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Reinhard Zumkeller, Aug 10 2001
STATUS
approved