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 A255694 Primes p such that five iterations of the map p->2p+nextprime(p) give primes. 1
 1538419, 3662941, 10835789, 11698837, 13441633, 16002521, 19039199, 28598753, 29170307, 57766903, 58309837, 60324577, 71197453, 75817459, 84834049, 86506051, 127779919, 130415413, 184465669, 189978779, 221705713, 230700227, 231203779, 239519327, 255285439 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Apparently there is no limit for number of iterations of the map p->2p+nextprime(p) all giving primes. E.g., first primes with 6 iterations all giving primes are 1854811727,1988791547,2498711497,2866433161,3337303943,3514209079. LINKS EXAMPLE p=1538419, q=2p+np(p)=4615267, r=2q+np(q)=13845817, s=2r+np(r)=41537491, t=2s+np(s)=124612483, u=2t+np(t)=373837459 all prime, while v=2u+np(u)=1121512407=3*23*89*182627 is not prime; here np(m) = A151800(m) = next prime after m. CROSSREFS Subsequence of A173971. Cf. A151800. Sequence in context: A126252 A268305 A236117 * A089492 A253034 A328563 Adjacent sequences:  A255691 A255692 A255693 * A255695 A255696 A255697 KEYWORD nonn AUTHOR Zak Seidov, Mar 15 2015 STATUS approved

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Last modified May 11 18:21 EDT 2021. Contains 343808 sequences. (Running on oeis4.)