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A124190
a(n) is the largest prime < 4*a(n-1) for n > 1, with a(1) = 2.
3
2, 7, 23, 89, 353, 1409, 5623, 22483, 89923, 359663, 1438643, 5754571, 23018273, 92073083, 368292317, 1473169213, 5892676849, 23570707387, 94282829533, 377131318127, 1508525272477, 6034101089897, 24136404359569, 96545617438253, 386182469752993, 1544729879011951
OFFSET
1,1
LINKS
Artur Jasinski, Dec 16 2006, Table of n, a(n) for n = 1..40
MATHEMATICA
NestList[NextPrime[4#, -1]&, 2, 30] (* Harvey P. Dale, Oct 11 2023 *)
CROSSREFS
Cf. A126031.
Sequence in context: A001338 A150341 A150342 * A176578 A150343 A150344
KEYWORD
nonn,changed
AUTHOR
Artur Jasinski, Dec 16 2006
STATUS
approved