The OEIS is supported by the many generous donors to the OEIS Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A221158 Fibonacci numbers with two 1's in the binary representation. 3
 3, 5, 34, 144 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Fibonacci numbers of the form 2^a + 2^b, a>b. Elkies (2014) proved that there are no other terms. This sequence is one row of A222296. - T. D. Noe, Mar 08 2013 LINKS Noam D. Elkies, Fibonacci numbers with Hamming weight 2, Mathoverflow, 2014. EXAMPLE 144 = 128 + 16 = 2^7 + 2^4, thus it is in the sequence. MATHEMATICA Select[Fibonacci[Range], DigitCount[#, 2, 1] == 2 &] (* Alonso del Arte, Feb 21 2013 *) PROG (Python) prev = 0 curr = 1 for n in range(3000000):   c = 0         # count 1's   p = 1   while p<=prev:     c += ((prev & p) > 0)     if c>2:       break     p += p   if n&1023==0:     print '.',   if c==2:     print prev,   prev, curr = curr, prev+curr CROSSREFS Cf. A000045, A004685, A222296. Sequence in context: A222484 A222630 A187993 * A068111 A162444 A305858 Adjacent sequences:  A221155 A221156 A221157 * A221159 A221160 A221161 KEYWORD nonn,full,fini AUTHOR Alex Ratushnyak, Feb 20 2013 EXTENSIONS full, fini keywords added by Max Alekseyev, May 13 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 22 01:28 EST 2022. Contains 350481 sequences. (Running on oeis4.)