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A204904 p(n)-q(n), where (p(n), q(n)) is the least pair of odd primes for which n divides p(n)-q(n).

%I A204904 #25 Mar 14 2018 17:41:44
%S A204904 2,2,6,4,10,6,14,8,18,10,22,12,26,14,30,16,34,18,38,20,42,22,46,24,50,
%T A204904 26,54,28,58,30,62,32,66,34,70,36,74,38,78,40,82,42,86,44,90,46,94,48,
%U A204904 98,50,102,52,106,54,110,56,114,58,118,60,122,62,126,64,130
%N A204904 p(n)-q(n), where (p(n), q(n)) is the least pair of odd primes for which n divides p(n)-q(n).
%C A204904 This sequence agrees with A109043 for 0<n<=65; what about all larger n?
%C A204904 For a guide to related sequences, see A204892.
%C A204904 Sequence agrees with A109043 at least up to 6400. - _Michel Marcus_, Mar 14 2018
%C A204904 If Polignac's conjecture is true, then this is a duplicate of A109043. - _Robert Israel_, Mar 14 2018
%H A204904 Wikipedia, <a href="https://en.wikipedia.org/wiki/Polignac%27s_conjecture">Polignac's conjecture</a>
%e A204904 1 = (5-3)/2=(7-3)/4=(13-3)/6=(11-3)/8=...
%e A204904 2 = (5-3)/1=(11-5)/3=(7-3)/5=(17-3)/7=...
%t A204904 (See the program at A204900.)
%o A204904 (PARI) a(n) = {forprime(p=5,,forprime(q=3, p-1, d = p-q; if ((d % n) == 0, return (d));););} \\ _Michel Marcus_, Mar 14 2018
%Y A204904 Cf. A066043, A109043, A204900, A204892, A210530.
%K A204904 nonn
%O A204904 1,1
%A A204904 _Clark Kimberling_, Jan 20 2012