login
The part of n in base phi left of the decimal point, using a greedy algorithm representation (more precisely, using the Bergman-canonical representation).
17

%I #37 Oct 20 2023 08:41:27

%S 0,1,10,100,101,1000,1010,10000,10001,10010,10100,10101,100000,100010,

%T 100100,100101,101000,101010,1000000,1000001,1000010,1000100,1000101,

%U 1001000,1001010,1010000,1010001,1010010,1010100,1010101,10000000

%N The part of n in base phi left of the decimal point, using a greedy algorithm representation (more precisely, using the Bergman-canonical representation).

%H T. D. Noe, <a href="/A105424/b105424.txt">Table of n, a(n) for n = 0..1000</a>

%H F. Michel Dekking, <a href="https://arxiv.org/abs/2002.01665">How to add two natural numbers in base phi</a>, arXiv:2002.01665 [math.NT], 5 Feb 2020.

%H Ron Knott, <a href="http://www.maths.surrey.ac.uk/hosted-sites/R.Knott/Fibonacci/phigits.html">Phigits and the Base Phi representation</a>.

%H Ron Knott, <a href="/A105424/a105424.pdf">Phigits and the Base Phi representation</a> [Local copy, pdf only]

%H Jeffrey Shallit, <a href="https://arxiv.org/abs/2305.02672">Proving Properties of phi-Representations with the Walnut Theorem-Prover</a>, arXiv:2305.02672 [math.NT], 2023. [Note that this document has been revised multiple times.]

%e 2 = 10.01 in base phi, so left of the decimal point is 10.

%e The first few numbers written in base phi:

%e 0 = 0.

%e 1 = 1.

%e 2 = 10.01

%e 3 = 100.01

%e 4 = 101.01

%e 5 = 1000.1001

%e 6 = 1010.0001

%e 7 = 10000.0001

%e 8 = 10001.0001

%e 9 = 10010.0101

%e 10 = 10100.0101

%e 11 = 10101.0101

%e 12 = 100000.101001

%e 13 = 100010.001001

%e 14 = 100100.001001

%e 15 = 100101.001001

%e 16 = 101000.100001

%e 17 = 101010.000001

%e 18 = 1000000.000001

%e 19 = 1000001.000001

%e 20 = 1000010.010001

%e 21 = 1000100.010001

%e 22 = 1000101.010001

%e 23 = 1001000.100101

%e 24 = 1001010.000101

%e ...

%t nn = 1000; len = 2*Ceiling[Log[GoldenRatio, nn]]; Table[d = RealDigits[n, GoldenRatio, len]; FromDigits[Take[d[[1]], d[[2]]]], {n, 0, nn}] (* _T. D. Noe_, May 20 2011 *)

%Y Cf. A001622, A055778, A105425, A104605.

%Y See A341722 for the part to the right of the decimal point.

%Y Cf. A105116 (base e), A344939 (base Pi).

%K nonn,base

%O 0,3

%A Bryan Jacobs (bryanjj(AT)gmail.com), Apr 08 2005

%E Definition clarified by _N. J. A. Sloane_, May 27 2023