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 A053840 #43 Aug 09 2024 05:09:24 %S A053840 0,1,2,3,4,1,2,3,4,0,2,3,4,0,1,3,4,0,1,2,4,0,1,2,3,1,2,3,4,0,2,3,4,0, %T A053840 1,3,4,0,1,2,4,0,1,2,3,0,1,2,3,4,2,3,4,0,1,3,4,0,1,2,4,0,1,2,3,0,1,2, %U A053840 3,4,1,2,3,4,0,3,4,0,1,2,4,0,1,2,3,0,1,2,3,4,1,2,3,4,0,2,3,4,0,1,4,0,1,2,3 %N A053840 (Sum of digits of n written in base 5) modulo 5. %C A053840 a(n) is the fourth row of the array in A141803. - _Andrey Zabolotskiy_, May 16 2016 %H A053840 Michael De Vlieger, <a href="/A053840/b053840.txt">Table of n, a(n) for n = 0..10000</a> %H A053840 Glen Joyce C. Dulatre, Jamilah V. Alarcon, Vhenedict M. Florida and Daisy Ann A. Disu, <a href="http://docplayer.net/87034980-Vol-15-no-2-april-2017-dmmmsu-cas-science-monitor.html">On Fractal Sequences</a>, DMMMSU-CAS Science Monitor (2016-2017) Vol. 15 No. 2, 109-113. %H A053840 Robert Walker, <a href="http://robertinventor.com/ftswiki/Self_Similar_Sloth_Canon_Number_Sequences">Self Similar Sloth Canon Number Sequences</a> %F A053840 a(n) = A010874(A053824(n)). - _Andrey Zabolotskiy_, May 18 2016 %t A053840 Mod[Total@ IntegerDigits[#, 5], 5] & /@ Range[0, 120] (* _Michael De Vlieger_, May 17 2016 *) %o A053840 (PARI) a(n) = vecsum(digits(n,5)) % 5; \\ _Michel Marcus_, May 16 2016 %Y A053840 Cf. A010874, A053824, A141803. %Y A053840 Cf. A010060, A053837-A053844. %K A053840 base,nonn %O A053840 0,3 %A A053840 _Henry Bottomley_, Mar 28 2000