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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

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Last modified October 16 12:35 EDT 2018. Contains 316263 sequences. (Running on oeis4.)