This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A183132 Successive integers produced by Conway's PRIMEGAME using Kilminster's Fractran program with only nine fractions. 4

%I

%S 10,5,36,858,234,5577,1521,3549,8281,910,100,50,25,180,3388,924,252,

%T 6006,1638,39039,10647,24843,57967,6370,700,300,7150,1950,46475,12675,

%U 29575,3250,360,6776,1848,504,12012,3276,78078,21294,507507,138411,322959,753571

%N Successive integers produced by Conway's PRIMEGAME using Kilminster's Fractran program with only nine fractions.

%C The exponents of exact powers of 10 in this sequence are 1, followed by the successive primes (A008578).

%D D. Olivastro, Ancient Puzzles. Bantam Books, NY, 1993, p. 21.

%H Alois P. Heinz, <a href="/A183132/b183132.txt">Table of n, a(n) for n = 1..10547</a>

%H J. H. Conway, <a href="http://dx.doi.org/10.1007/978-1-4612-4808-8_2">FRACTRAN: a simple universal programming language for arithmetic</a>, in T. M. Cover and Gopinath, eds., Open Problems in Communication and Computation, Springer, NY 1987, pp. 4-26.

%H Esolang wiki, <a href="http://www.esolangs.org/wiki/Fractran">Fractran</a>

%H Chaim Goodman-Strauss, <a href="http://www.ams.org/notices/201003/rtx100300343p.pdf">Can’t Decide? Undecide!</a>, Notices of the AMS, Volume 57, Number 3, pp. 343-356, March 2010.

%H R. K. Guy, <a href="http://www.jstor.org/stable/2690263">Conway's prime producing machine</a>, Math. Mag. 56 (1983), no. 1, 26-33.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/FRACTRAN.html">FRACTRAN</a>.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/FRACTRAN">FRACTRAN</a>.

%p l:= [3/11, 847/45, 143/6, 7/3, 10/91, 3/7, 36/325, 1/2, 36/5]:

%p a:= proc(n) option remember;

%p global l;

%p local p, k;

%p if n=1 then 10

%p else p:= a(n-1);

%p for k while not type(p*l[k], integer)

%p do od; p*l[k]

%p fi

%p end:

%p seq(a(n), n=1..50);

%t l = {3/11, 847/45, 143/6, 7/3, 10/91, 3/7, 36/325, 1/2, 36/5};

%t a[n_] := a[n] = Module[{p, k}, If[n == 1, 10, p = a[n - 1]; For[k = 1, !IntegerQ[p*l[[k]]], k++]; p*l[[k]]]];

%t Array[a, 50] (* _Jean-François Alcover_, May 28 2018, from Maple *)

%Y Cf. A183133, A008578, A007542, A007546, A007547.

%K easy,look,nonn

%O 1,1

%A _Alois P. Heinz_, Dec 26 2010

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 15 18:22 EDT 2019. Contains 328037 sequences. (Running on oeis4.)