A063714 Values of r occurring in A063713.

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

Robert Israel, Table of n, a(n) for n = 1..10000

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

Cf. A063713, A002373, A020483.

Sequence in context: A202106 A136019 A242017 * A235649 A113965 A162277

Adjacent sequences: A063711 A063712 A063713 * A063715 A063716 A063717

Keyword

nonn,look

Author

Reinhard Zumkeller, Aug 10 2001

Status

approved