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 A086076 #7 Dec 15 2017 17:36:32 %S A086076 0,0,0,0,0,1,0,0,0,1,2,0,0,0,1,0,0,1,0,0,0,0,1,0,0,1,1,0,0,1,1,0,1,1, %T A086076 2,0,0,0,0,0,0,0,0,0,0,1,0,0,0,1,1,0,0,0,1,1,1,1,0,0,0,0,1,0,0,1,0,0, %U A086076 0,1,1,2,0,0,1,1,0,0,0,0,0,0,0,0,1,2,0,0,0,1,1,0,0,0,1,1,1,1,1,1,2,2,2,2,1 %N A086076 Number of 5's in decimal expansion of triangular number n(n+1)/2. %t A086076 DigitCount[#,10,5]&/@Accumulate[Range[0,110]] (* _Harvey P. Dale_, Sep 24 2016 *) %Y A086076 Cf. 0's A086071, 1's A086072, 2's A086073, 3's A086074, 4's A086075, 6's A086077, 7's A086078, 8's A086079, 9's A086080. %K A086076 base,nonn %O A086076 0,11 %A A086076 _Jason Earls_, Jul 08 2003