A072305 a(n)-th Fibonacci number is the smallest Fibonacci number containing exactly n 1's.

1, 19, 22, 71, 82, 118, 119, 200, 241, 218, 271, 350, 377, 362, 419, 473, 544, 578, 562, 753, 622, 682, 687, 844, 775, 746, 830, 745, 908, 1012, 922, 979, 1141, 1227, 1201, 1161, 1179, 1273, 1396, 1190, 1415, 1314, 1369, 1486, 1507, 1531, 1667, 1867, 1714

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..200

Example

a(3)=22 since 22nd Fibonacci number i.e. 17711 contains exactly 3, 1's.

Mathematica

Module[{nn=2000, fi}, fi=Table[{n, DigitCount[Fibonacci[n], 10, 1]}, {n, nn}]; Table[ SelectFirst[fi, #[[2]]==k&], {k, 50}]][[All, 1]] (* Harvey P. Dale, Sep 25 2019 *)

Crossrefs

Cf. A000045.

Sequence in context: A335347 A050955 A303299 * A095222 A343740 A317254

Adjacent sequences: A072302 A072303 A072304 * A072306 A072307 A072308

Keyword

base,nonn

Author

Shyam Sunder Gupta, Jul 14 2002

Extensions

a(20)-a(49) from Alois P. Heinz, Apr 26 2017

Status

approved