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A175122
a(1)=3. a(n) = smallest prime > a(n-1) such that a(n)-a(n-1) = 2*m, where m is composite.
2
3, 11, 19, 31, 43, 59, 67, 79, 97, 109, 127, 139, 151, 163, 179, 191, 199, 211, 223, 239, 251, 263, 271, 283, 307, 331, 347, 359, 367, 379, 397, 409, 421, 433, 449, 457, 487, 499, 523, 541, 557, 569, 577, 593, 601, 613, 631, 643, 659, 677, 701, 709, 727, 739
OFFSET
1,1
COMMENTS
A175123(n)*2 = a(n+1) - a(n).
LINKS
MATHEMATICA
spn[n_]:=Module[{k=NextPrime[n]}, While[!CompositeQ[(k-n)/2], k= NextPrime[ k]]; k]; NestList[spn, 3, 60] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 30 2019 *)
CROSSREFS
Cf. A175123.
Sequence in context: A125994 A137295 A038536 * A031369 A014223 A023265
KEYWORD
nonn
AUTHOR
Leroy Quet, Feb 15 2010
EXTENSIONS
Extended by Ray Chandler, Mar 06 2010
STATUS
approved