A105502 Numbers m such that 2 is the leading digit of the m-th Fibonacci number in decimal representation.

3, 8, 13, 18, 23, 32, 37, 42, 47, 51, 56, 61, 66, 75, 80, 85, 90, 99, 104, 109, 114, 118, 123, 128, 133, 142, 147, 152, 157, 166, 171, 176, 185, 190, 195, 200, 209, 214, 219, 224, 233, 238, 243, 252, 257, 262, 267, 276, 281, 286, 291, 295, 300, 305, 310, 319

Offset

1,1

Comments

A008963(a(n)) = 2; A105512(a(n)) = A105512(a(n) - 1) + 1.

Links

Winston de Greef, Table of n, a(n) for n = 1..10000

Formula

a(n) ~ kn by the equidistribution theorem, where k = log(10)/(log(3) - log(2)) = 5.67887.... - Charles R Greathouse IV, Oct 07 2016

Example

a(10)=51: A008963(51) = A000030(A000045(51)) = A000030(20365011074) = 2.

Mathematica

Select[Range[400], First[IntegerDigits[Fibonacci[#]]]==2&] (* Harvey P. Dale, Jul 13 2015 *)

Prog

(PARI) is(n)=digits(fibonacci(n))[1]==2 \\ Charles R Greathouse IV, Oct 07 2016

Crossrefs

Cf. A000030, A000045, A072682, A105501, A105503, A105504, A105505, A105506, A105507, A105508, A105509.

Sequence in context: A277600 A016885 A190517 * A105702 A184739 A081989

Adjacent sequences: A105499 A105500 A105501 * A105503 A105504 A105505

Keyword

nonn,base

Author

Reinhard Zumkeller, Apr 11 2005

Status

approved