A072308 a(n)-th Fibonacci number is the smallest Fibonacci number containing exactly n 4's.

9, 12, 67, 43, 78, 144, 182, 220, 206, 309, 354, 287, 350, 316, 420, 423, 515, 551, 591, 667, 691, 595, 798, 608, 824, 789, 790, 1079, 839, 1030, 1022, 1050, 1195, 1100, 1253, 1217, 1307, 1152, 1293, 1466, 1397, 1436, 1611, 1521, 1738, 1749, 1645, 1721, 1725

Offset

1,1

Links

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

Example

a(2)=12 since 12th Fibonacci number i.e. 144 contains exactly two 4's.

Mathematica

With[{fibs=Fibonacci[Range[5000]]}, Flatten[Table[Position[fibs, _?(DigitCount[ #, 10, 4]==n&)][[1]], {n, 50}]]] (* Harvey P. Dale, Jan 26 2013 *)

Crossrefs

Sequence in context: A253088 A341208 A328120 * A140145 A166643 A038302

Adjacent sequences: A072305 A072306 A072307 * A072309 A072310 A072311

Keyword

base,nonn

Author

Shyam Sunder Gupta, Jul 14 2002

Extensions

More terms from Harvey P. Dale, Jan 26 2013

Status

approved