A136610 Number of odd digits in Fibonacci numbers.

0, 1, 1, 0, 1, 1, 0, 2, 1, 1, 2, 1, 1, 2, 3, 1, 2, 4, 1, 2, 2, 2, 5, 2, 1, 3, 5, 3, 5, 3, 1, 3, 4, 4, 3, 3, 5, 5, 4, 3, 6, 5, 4, 5, 5, 7, 7, 7, 4, 5, 4, 5, 6, 9, 5, 6, 8, 6, 7, 4, 6, 7, 8, 7, 7, 9, 7, 7, 5, 7, 10, 8, 6, 10, 8, 9, 6, 10, 8, 6, 6

Offset

0,8

Links

Table of n, a(n) for n=0..80.

Ron Knott, The Fibonacci numbers.

Formula

a(n) = A196564(A000045(n)). - Michel Marcus, May 06 2025

a(n) = A060384(n) - A138468(n). - James C. McMahon, Jun 07 2025

Example

1597 = Fibonacci(17) and has four odd digits, so a(17) = 4.

Maple

nodss := proc(n) local dgs, d; dgs := convert(n, base, 10) ; add( d mod 2, d=dgs) ; end: A136610 :=proc(n) nodss(combinat[fibonacci](n)) ; end: seq( A136610(n), n=0..80) ; # R. J. Mathar, Jul 08 2009

Mathematica

a[n_]:=Total[Boole[OddQ/@IntegerDigits[Fibonacci[n]]]] (* James C. McMahon, May 06 2025 *)

Crossrefs

Cf. A000045, A138468, A196564.

Cf. A060384, A085855. - R. J. Mathar, Jul 08 2009

Sequence in context: A385685 A241911 A335221 * A377365 A326371 A226304

Adjacent sequences: A136607 A136608 A136609 * A136611 A136612 A136613

Keyword

nonn,base

Author

Parthasarathy Nambi, May 11 2008

Extensions

a(13) corrected and more terms added by R. J. Mathar, Jul 08 2009

Status

approved