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 A086013 #16 Dec 15 2017 17:36:31 %S A086013 0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,1,1,1,0,0,0,0,0,0,0,0, %T A086013 1,1,0,0,0,1,0,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,1,0, %U A086013 0,0,0,1,1,1,1,2,1,1,0,0,0,1,0,0,1,1,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0 %N A086013 Number of 5's in decimal expansion of n^2. %H A086013 G. C. Greubel, <a href="/A086013/b086013.txt">Table of n, a(n) for n = 0..1000</a> %t A086013 DigitCount[(Range[0,110])^2,10,5] (* _Harvey P. Dale_, Jul 26 2016 *) %o A086013 (PARI) A086013(n)=#select(d->d==5,digits(n^2)) \\ _M. F. Hasler_, Feb 21 2016 %Y A086013 Cf. 0's A086008, 1's A086009, 2's A086010, 3's A086011, 4's A086012, 6's A086014, 7's A086015, 8's A086016, 9's A086017. %Y A086013 Cf. A269245 for the n^3 analog. %K A086013 base,nonn %O A086013 0,76 %A A086013 _Jason Earls_, Jul 07 2003