cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A214853 Fibonacci numbers with only one 0 in the binary representation.

Original entry on oeis.org

0, 2, 5, 13, 55
Offset: 1

Views

Author

Alex Ratushnyak, Mar 08 2013

Keywords

Comments

Conjecture: the sequence is finite.
No more terms below 2*10^301. - Matthew House, Sep 06 2015
No more terms below 10^162809483. (This number could easily be raised. Of the Fibonacci numbers less than 2^32 -- i.e., F(0) through F(47) -- F(10)=55 is the largest that has only one 0 in its binary representation, and of those not less than 2^32, the smallest one whose 32 least significant bits include fewer than 2 zero bits is Fibonacci(779038816), which exceeds 10^162809483.) - Jon E. Schoenfield, Sep 07 2015

Examples

			55 is 110111 in binary, thus 55 is in the sequence.
		

Crossrefs

Intersection of A030130 and A000045.

Programs

  • Mathematica
    Select[Fibonacci@ Range[0, 120], Last@ DigitCount[#, 2] == 1 &] (* Michael De Vlieger, Sep 07 2015 *)
  • Python
    def count0(x):
        c = 0
        while x:
            c+= 1 - (x&1)
            if c>1:
                return 2
            x>>=1
        return c
    prpr, prev = 0,1
    TOP = 1<<12
    print(0, end=',')
    for i in range(1,TOP):
        if count0(prpr)==1:
            print(prpr, end=',')
        if (i&4095)==0:
            print('.', end=',')
        prpr, prev = prev, prpr+prev