Fractran
Fractran is an algorithm applied to a given list 
, 
, ..., 
of Fractions. Given a startingInteger 
, the Fractran algorithm proceeds by repeatedly multiplying the integer at a given stage by thefirst element 
given an integer Product. The algorithm terminates when there is no such .
The list
with starting integer
generates a sequence 2, 15, 825, 725, 1925, 2275, 425, 390, 330, 290, 770, ... (Sloane's A007542). Conway (1987)showed that the only other powers of 2 which occur are those with Prime exponent: 
, 
, 
, 
, ....
References
Conway, J. H. ``Unpredictable Iterations.'' In Proc. Number Theory Conf., Boulder, CO, pp. 49-52, 1972. Conway, J. H. ``Fractran: A Simple Universal Programming Language for Arithmetic.'' Ch. 2 in Open Problems in Communication and Computation (Ed. T. M. Cover and B. Gopinath). New York: Springer-Verlag, pp. 4-26, 1987. Sloane, N. J. A. SequenceA007542/M2084in ``An On-Line Version of the Encyclopedia of Integer Sequences.''http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S.The Encyclopedia of Integer Sequences. San Diego: Academic Press, 1995.
- Cone Net
- Cone (Space)
- Cone-Sphere Intersection
- Confidence Interval
- Configuration
- Confluent Hypergeometric Differential Equation
- Confluent Hypergeometric Function
- Confluent Hypergeometric Function of the First Kind
- Confluent Hypergeometric Function of the Second Kind
- Confluent Hypergeometric Limit Function
- Confocal Conics
- Confocal Ellipsoidal Coordinates
- Confocal Parabolic Coordinates
- Confocal Paraboloidal Coordinates
- Conformal Latitude
- Conformal Map
- Conformal Solution
- Conformal Tensor
- Conformal Transformation
- Congruence
- Congruence Axioms
- Congruence (Geometric)
- Congruence Transformation
- Congruent
- Congruent Incircles Point