login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A176253 Indices n corresponding to Fibonacci numbers Fib(n) whose decimal expansion does not contain the digit "5". 9
1, 2, 3, 4, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 19, 21, 22, 24, 26, 27, 28, 30, 31, 32, 38, 42, 43, 44, 45, 46, 49, 68, 69, 78, 79, 81, 86, 88, 89, 90, 94, 97, 102, 116, 117, 137, 161, 164, 285 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Probability that a Fibonacci number Fib(n) (expressed in usual decimal base) contains no digit 5 approaches zero as n goes to infinity.

LINKS

Table of n, a(n) for n=1..49.

EXAMPLE

For n=5 a(5)=6 since fib(6)=8 is the 5th Fibonacci containing no 5s (1,1,2,3,4,8,...).

MATHEMATICA

Select[Range[1, 300], DigitCount[Fibonacci[#], 10, 5]==0&] (* Vincenzo Librandi, May 10 2019 *)

PROG

(PARI) isok(n) = {digs = digits(fibonacci(n)); for (i = 1, #digs, if (digs[i] == 5, return (0)); ); return (1); } \\ Michel Marcus, Sep 02 2013

(MAGMA) [n: n in [1..30000] | not 5 in Intseq(Fibonacci(n))]; // Vincenzo Librandi, May 10 2019

CROSSREFS

Cf. A000045,

Sequence in context: A244219 A039258 A187968 * A277644 A039199 A172269

Adjacent sequences:  A176250 A176251 A176252 * A176254 A176255 A176256

KEYWORD

nonn,base

AUTHOR

Carmine Suriano, Apr 13 2010

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 16 05:06 EDT 2022. Contains 353690 sequences. (Running on oeis4.)