login
The least prime q > p for which n = p + q - r for some prime r, where p = A270003(n).
3

%I #7 Apr 29 2016 17:31:58

%S 5,3,3,5,5,7,7,11,11,11,11,13,13,17,17,17,17,19,19,23,23,23,23,29,29,

%T 29,29,29,29,31,31,37,37,37,37,37,37,41,41,41,41,43,43,47,47,47,47,53,

%U 53,53,53,53,53,59,59,59,59,59,59,61,61,67,67,67,67,67

%N The least prime q > p for which n = p + q - r for some prime r, where p = A270003(n).

%H Clark Kimberling, <a href="/A270753/b270753.txt">Table of n, a(n) for n = 1..10000</a>

%e n p q r

%e 1 3 5 7

%e 2 2 3 3

%e 3 2 3 2

%e 4 2 5 3

%e 5 2 5 2

%e 6 2 7 3

%e 7 2 7 2

%t t = Join[{{1, {3, 5, 7}}, {2, {2, 3, 3}}}, Table[If[PrimeQ[n], {n, {2, n, 2}}, p = If[EvenQ[2 + NextPrime[n, 1] - n], 3, 2]; NestWhile[# + 1 &, 1, ! PrimeQ[r = (p + (q = NextPrime[n, #])) - n] &]; {n, {p, q, r}}], {n, 3, 300}]];

%t Map[#[[2]][[1]] &, t] (* p, A270003 *)

%t Map[#[[2]][[2]] &, t] (* q, A270753 *)

%t Map[#[[2]][[3]] &, t] (* r, A271353 *)

%t (* _Peter J. C. Moses_, Apr 26 2016 *)

%Y Cf. A000040, A270003, A271353.

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, Apr 26 2016