A238327 - OEIS

%I #16 Mar 08 2014 08:58:25

%S 1,4,7,13,19,25,31,39,43,49,55,61,69,73,81,85,91,99,103,109,115,129,

%T 133,139,151,159,165,169,175,181,193,199,213,225,229,235,241,253,259,

%U 265,271,279,283,295,309,313,319,333,339,349,355,361,369,375,381,385,391,399,403

%N Recursively defined by a(0) = 1, a(n + 1) = p + 2, where p is the least prime greater than a(n).

%C When a(n) is prime, it is the second member of a twin prime pair. Moreover, every twin prime pair except 3,5 is found in this manner.

%C All members between 7 and 333 are also in A076974. - _Ralf Stephan_, Feb 28 2014

%H Reinhard Zumkeller, <a href="/A238327/b238327.txt">Table of n, a(n) for n = 0..10000</a>

%F a(n+1) = A151800(a(n)) + 2. - _Reinhard Zumkeller_, Feb 28 2014

%t a[0] := 1; a[n_] := a[n] = Prime[PrimePi[a[n - 1]] + 1] + 2; Table[a[n], {n, 0, 59}] (* _Alonso del Arte_, Feb 24 2014 *)

%o (Haskell)

%o a238327 n = a238327_list !! n

%o a238327_list = iterate ((+ 2) . a151800) 1

%o -- _Reinhard Zumkeller_, Feb 28 2014

%K nonn

%O 0,2

%A _Curtis Herink_, Feb 24 2014