OFFSET
1,1
FORMULA
a(n) ~ kn by the equidistribution theorem, where k = log(10)/(log(4) - log(3)) = 8.00392.... - Charles R Greathouse IV, Oct 07 2016
MATHEMATICA
Select[Table[{n, Fibonacci[n]}, {n, 450}], First[IntegerDigits[#[[2]]]]==3&][[All, 1]] (* Harvey P. Dale, Apr 13 2019 *)
PROG
(PARI) is(n)=digits(fibonacci(n))[1]==3 \\ Charles R Greathouse IV, Oct 07 2016
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Apr 11 2005
EXTENSIONS
Definition clarified by Harvey P. Dale, Apr 13 2019
STATUS
approved