This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A085856 #15 Nov 22 2020 08:09:05
%S A085856 0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,1,1,0,0,2,1,1,1,1,
%T A085856 1,2,1,1,0,1,1,0,2,0,0,0,0,2,1,1,3,1,2,1,3,1,2,2,2,3,1,1,1,1,2,0,2,2,
%U A085856 3,0,1,2,1,0,1,1,2,1,1,4,2,1,1,0,0,3,2,2,0,0,2,0,1,3,4,0,2,3,1,4,3,0,3,3,5
%N A085856 Number of 2's in decimal expansion of Fibonacci(n).
%H A085856 Robert Israel, <a href="/A085856/b085856.txt">Table of n, a(n) for n = 0..10000</a>
%e A085856 Fibonacci(33) = 3524578, so a(33)=1.
%e A085856 Fibonacci(87) = 679891637638612258, so a(87)=2.
%p A085856 f:= n -> numboccur(2,convert(combinat:-fibonacci(n),base,10)):
%p A085856 map(f, [$0..200]); # _Robert Israel_, Nov 22 2020
%t A085856 Table[DigitCount[Fibonacci[n]][[2]], {n, 0, 200}] (* _Vladimir Joseph Stephan Orlovsky_, Jul 01 2011 *)
%Y A085856 Cf. 0's A085854, 1's A085855, 3's A085857, 4's A085858, 5's A085859, 6's A085860, 7's A085861, 8's A085862, 9's A085863.
%K A085856 base,nonn
%O A085856 0,30
%A A085856 _Jason Earls_, Jul 06 2003