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A183133 Number of steps to compute the n-th prime in PRIMEGAME using Kilminster's Fractran program with only nine fractions. 3
10, 46, 196, 500, 1428, 2488, 4588, 6840, 10546, 17118, 23064, 33332, 44472, 55848, 70330, 90836, 115136, 137912, 168802, 201000, 233542, 276680, 320332, 373198, 439722, 503810, 568334, 640092, 712314, 792186, 917090, 1023878, 1146632, 1263818, 1419298 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

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

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..100

J. H. Conway, FRACTRAN: a simple universal programming language for arithmetic, in T. M. Cover and Gopinath, eds., Open Problems in Communication and Computation, Springer, NY 1987, pp. 4-26.

Esolang wiki "Fractran".

Chaim Goodman-Strauss, Can’t Decide? Undecide!, Notices of the AMS, Volume 57, Number 3, pp. 343-356, March 2010.

R. K. Guy, Conway's prime producing machine, Math. Mag. 56 (1983), no. 1, 26-33.

Eric Weisstein's World of Mathematics, FRACTRAN.

Wikipedia, FRACTRAN.

MAPLE

a:= proc(n) option remember;

      local l, p, m, k;

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

      if n=1 then b(0):= 10; a(0):= 0

             else a(n-1)

      fi;

      p:= b(n-1);

      for m do

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

         do od; p:= p*l[k];

         if 10^ilog10(p)=p then break fi

      od:

      b(n):= p;

      m + a(n-1)

    end:

seq(a(n), n=1..20);

CROSSREFS

Cf. A183132, A008578, A007542, A007546, A007547.

Sequence in context: A003197 A096045 A287090 * A115712 A199313 A003765

Adjacent sequences:  A183130 A183131 A183132 * A183134 A183135 A183136

KEYWORD

easy,nonn

AUTHOR

Alois P. Heinz, Dec 26 2010

STATUS

approved

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Last modified February 17 17:12 EST 2019. Contains 320222 sequences. (Running on oeis4.)