A219641 a(n) = n minus (number of 1's in Zeckendorf expansion of n).

0, 0, 1, 2, 2, 4, 4, 5, 7, 7, 8, 9, 9, 12, 12, 13, 14, 14, 16, 16, 17, 20, 20, 21, 22, 22, 24, 24, 25, 27, 27, 28, 29, 29, 33, 33, 34, 35, 35, 37, 37, 38, 40, 40, 41, 42, 42, 45, 45, 46, 47, 47, 49, 49, 50, 54, 54, 55, 56, 56, 58, 58, 59, 61, 61, 62, 63, 63, 66

Offset

0,4

Comments

See A014417 for the Fibonacci number system representation, also known as Zeckendorf expansion.

Links

Antti Karttunen, Table of n, a(n) for n = 0..10000

Paul Baird-Smith, Alyssa Epstein, Kristen Flint, and Steven J. Miller, The Zeckendorf Game, arXiv:1809.04881 [math.NT], 2018.

Formula

a(n) = n - A007895(n).

Mathematica

zeck = DigitCount[Select[Range[0, 500], BitAnd[#, 2*#] == 0&], 2, 1];
Range[0, Length[zeck]-1] - zeck (* Jean-François Alcover, Jan 25 2018 *)

Prog

(Scheme): (define (A219641 n) (- n (A007895 n)))
(Python)
from sympy import fibonacci
def a(n):
    k=0
    x=0
    while n>0:
        k=0
        while fibonacci(k)<=n: k+=1
        x+=10**(k - 3)
        n-=fibonacci(k - 1)
    return str(x).count("1")
print([n - a(n) for n in range(101)]) # Indranil Ghosh, Jun 09 2017

Crossrefs

Cf. A007895, A014417. A022342 gives the positions of records, resulting the same sequence with duplicates removed: A219640. A035336 gives the positions of values that occur only once: A219639. Cf. also A219637, A219642. Analogous sequence for binary system: A011371, for factorial number system: A219651.

Sequence in context: A337765 A266690 A230421 * A341464 A277758 A240027

Adjacent sequences: A219638 A219639 A219640 * A219642 A219643 A219644

Keyword

nonn

Author

Antti Karttunen, Nov 24 2012

Status

approved