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 A007097 Primeth recurrence: a(n+1) = a(n)-th prime. (Formerly M0734) 263
 1, 2, 3, 5, 11, 31, 127, 709, 5381, 52711, 648391, 9737333, 174440041, 3657500101, 88362852307, 2428095424619, 75063692618249, 2586559730396077, 98552043847093519, 4123221751654370051, 188272405179937051081, 9332039515881088707361, 499720579610303128776791, 28785866289100396890228041 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS A007097(n) = Min {k : A109301(k) = n} = the first k whose rote height is n, the level set leader or minimum inverse function corresponding to A109301. - Jon Awbrey, Jun 26 2005 Lubomir Alexandrov informs me that he studied this sequence in his 1965 notebook. - N. J. A. Sloane, May 23 2008 a(n) is the Matula-Goebel number of the rooted path tree on n+1 vertices. The Matula-Goebel number of a rooted tree can be defined in the following recursive manner: to the one-vertex tree there corresponds the number 1; to a tree T with root degree 1 there corresponds the t-th prime number, where t is the Matula-Goebel number of the tree obtained from T by deleting the edge emanating from the root; to a tree T with root degree m>=2 there corresponds the product of the Matula-Goebel numbers of the m branches of T. - Emeric Deutsch, Feb 18 2012 Conjecture: log(a(1))*log(a(2))*...*log(a(n)) ~ a(n). - Thomas Ordowski, Mar 26 2015 REFERENCES Lubomir Alexandrov, unpublished notes, circa 1960. L. Longeri, Towards understanding nature and the aesthetics of prime numbers, https://www.longeri.org/prime/nature.html [Broken link, but leave the URL here for historical reasons] N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Lubomir Alexandrov, On the nonasymptotic prime number distribution, arXiv:math.NT/9811096, 1998. Lubomir Alexandrov, "The Eratosthenes Progression p(k+1)=π^{-1}(p(k)), k=0,1,2,..., p(0)=1,4,6,... Determines an Inner Prime Number Distribution Law", Second Int. Conf. "Modern Trends in Computational Physics", Jul 24-29, 2000, Dubna, Russia, Book of Abstracts, p. 19. Available at arXiv:math/0105154 [math.NT], 2001. Lubomir Alexandrov, Prime Number Sequences And Matrices Generated By Counting Arithmetic Functions, Communications of the Joint Institute of Nuclear Research, E5-2002-55, Dubna, 2002. J. Awbrey, Riffs and Rotes R. G. Batchko, A prime fractal and global quasi-self-similar structure in the distribution of prime-indexed primes, arXiv preprint arXiv:1405.2900 [math.GM], 2014. Peter R. Cappello, A Note on a Bijection between Natural Numbers and Rooted Trees, 4th SIAM Conference on Discrete Mathematics, June 1988.  See section 3 set S codes of paths (codes are per Matula-Goebel). M. Deléglise, Computation of large values of pi(x) N. Fernandez, An order of primeness, F(p) N. Fernandez, An order of primeness [cached copy, included with permission of the author] N. J. A. Sloane, My favorite integer sequences, in Sequences and their Applications (Proceedings of SETA '98). Robert G. Wilson v, Letter to N. J. A. Sloane, Sep. 1992 FORMULA A049084(a(n+1)) = a(n). - Reinhard Zumkeller, Jul 14 2013 a(n)/a(n-1) ~ log(a(n)) ~ prime(n). - Thomas Ordowski, Mar 26 2015 a(n) = prime^{[n]}(1), with the prime function prime(k) = A000040(k), with a(0) = 1. See the name and the programs. - Wolfdieter Lang, Apr 03 2018 Sum_{n>=1} 1/a(n) = A292667. - Amiram Eldar, Oct 15 2020 MAPLE seq((ithprime@@n)(1), n=0..10); # Peter Luschny, Oct 16 2012 MATHEMATICA NestList[Prime@# &, 1, 16] (* Robert G. Wilson v, May 30 2006 *) PROG (PARI) print1(p=1); until(, print1(", "p=prime(p)))  \\ M. F. Hasler, Oct 09 2011 (Haskell) a007097 n = a007097_list !! n a007097_list = iterate a000040 1  -- Reinhard Zumkeller, Jul 14 2013 (GAP) P:=Filtered([1..60000], IsPrime);; a:=;; for n in [2..10] do a[n]:=P[a[n-1]]; od; a; # Muniru A Asiru, Dec 22 2018 CROSSREFS Row 1 of array A114537. Left edge of tree A227413, right edge of A246378. Cf. A000040, A000720, A049076-A049081, A049084, A057450, A109301, A131842, A006450, A292667. Cf. A078442, A109082 (left inverses). Subsequence of A245823. Sequence in context: A090709 A112279 A130166 * A173422 A132745 A124538 Adjacent sequences:  A007094 A007095 A007096 * A007098 A007099 A007100 KEYWORD nonn,hard,nice AUTHOR EXTENSIONS a(15) corrected and a(16)-a(17) added by Paul Zimmermann a(18)-a(19) found by David Baugh using a program by Xavier Gourdon and Andrey V. Kulsha, Oct 25 2007 a(20)-a(21) found by Andrey V. Kulsha using a program by Xavier Gourdon, Oct 02 2011 a(22) from Henri Lifchitz, Oct 14 2014 a(23) from David Baugh using Kim Walisch's primecount, May 16 2016 STATUS approved

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Last modified September 27 13:46 EDT 2022. Contains 357062 sequences. (Running on oeis4.)