

A238327


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


1



1, 4, 7, 13, 19, 25, 31, 39, 43, 49, 55, 61, 69, 73, 81, 85, 91, 99, 103, 109, 115, 129, 133, 139, 151, 159, 165, 169, 175, 181, 193, 199, 213, 225, 229, 235, 241, 253, 259, 265, 271, 279, 283, 295, 309, 313, 319, 333, 339, 349, 355, 361, 369, 375, 381, 385, 391, 399, 403
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,2


COMMENTS

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.
All members between 7 and 333 are also in A076974.  Ralf Stephan, Feb 28 2014


LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000


FORMULA

a(n+1) = A151800(a(n)) + 2.  Reinhard Zumkeller, Feb 28 2014


MATHEMATICA

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 *)


PROG

(Haskell)
a238327 n = a238327_list !! n
a238327_list = iterate ((+ 2) . a151800) 1
 Reinhard Zumkeller, Feb 28 2014


CROSSREFS

Sequence in context: A111710 A191138 A075315 * A243811 A194073 A023496
Adjacent sequences: A238324 A238325 A238326 * A238328 A238329 A238330


KEYWORD

nonn


AUTHOR

Curtis Herink, Feb 24 2014


STATUS

approved



