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 A086071 #11 May 05 2024 19:30:43 %S A086071 1,0,0,0,1,0,0,0,0,0,0,0,0,0,1,1,0,0,0,1,1,0,0,0,2,0,0,0,1,0,0,0,0,0, %T A086071 0,1,0,1,0,1,1,0,1,0,1,1,1,0,0,0,0,0,0,0,0,1,0,0,0,1,1,0,0,1,2,0,0,0, %U A086071 0,0,0,0,0,1,0,1,0,2,1,1,1,0,1,0,1,0,0,0,0,2,1,0,0,0,0,1,0,0,0,1,2,0,0,0,1 %N A086071 Number of 0's in decimal expansion of triangular number n(n+1)/2. %H A086071 Paolo Xausa, <a href="/A086071/b086071.txt">Table of n, a(n) for n = 0..10000</a> %e A086071 tri(4)=10, so a(4)=1 and tri(24)=300, so a(24)=2. %t A086071 DigitCount[Accumulate[Range[0, 100]], 10, 0] (* _Paolo Xausa_, May 05 2024 *) %Y A086071 Cf. 1's A086072, 2's A086073, 3's A086074, 4's A086075, 5's A086076, 6's A086077, 7's A086078, 8's A086079, 9's A086080. %Y A086071 Cf. A000217. %K A086071 base,nonn %O A086071 0,25 %A A086071 _Jason Earls_, Jul 08 2003