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 A176253 #12 Sep 08 2022 08:45:52
%S A176253 1,2,3,4,6,7,8,9,11,12,13,14,15,16,19,21,22,24,26,27,28,30,31,32,38,
%T A176253 42,43,44,45,46,49,68,69,78,79,81,86,88,89,90,94,97,102,116,117,137,
%U A176253 161,164,285
%N A176253 Indices n corresponding to Fibonacci numbers Fib(n) whose decimal expansion does not contain the digit "5".
%C A176253 Probability that a Fibonacci number Fib(n) (expressed in usual decimal base) contains no digit 5 approaches zero as n goes to infinity.
%e A176253 For n=5 a(5)=6 since fib(6)=8 is the 5th Fibonacci containing no 5s (1,1,2,3,4,8,...).
%t A176253 Select[Range[1, 300], DigitCount[Fibonacci[#], 10, 5]==0&] (* _Vincenzo Librandi_, May 10 2019 *)
%o A176253 (PARI) isok(n) = {digs = digits(fibonacci(n)); for (i = 1, #digs, if (digs[i] == 5, return (0));); return (1);} \\ _Michel Marcus_, Sep 02 2013
%o A176253 (Magma) [n: n in [1..30000] | not 5 in Intseq(Fibonacci(n))]; // _Vincenzo Librandi_, May 10 2019
%Y A176253 Cf. A000045.
%K A176253 nonn,base
%O A176253 1,2
%A A176253 _Carmine Suriano_, Apr 13 2010