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 A053842 #29 Aug 09 2024 05:09:16
%S A053842 0,1,2,3,4,5,6,1,2,3,4,5,6,0,2,3,4,5,6,0,1,3,4,5,6,0,1,2,4,5,6,0,1,2,
%T A053842 3,5,6,0,1,2,3,4,6,0,1,2,3,4,5,1,2,3,4,5,6,0,2,3,4,5,6,0,1,3,4,5,6,0,
%U A053842 1,2,4,5,6,0,1,2,3,5,6,0,1,2,3,4,6,0,1,2,3,4,5,0,1,2,3,4,5,6,2,3,4,5,6,0,1
%N A053842 (Sum of digits of n written in base 7) modulo 7.
%C A053842 a(n) is the sixth row of the array in A141803. - _Andrey Zabolotskiy_, May 18 2016
%H A053842 G. C. Greubel, <a href="/A053842/b053842.txt">Table of n, a(n) for n = 0..5000</a>
%H A053842 Robert Walker, <a href="http://robertinventor.com/ftswiki/Self_Similar_Sloth_Canon_Number_Sequences">Self Similar Sloth Canon Number Sequences</a>
%F A053842 a(n) = A010876(A053828(n)). - _Andrey Zabolotskiy_, May 18 2016
%t A053842 Table[Mod[Plus @@ IntegerDigits[n, 7], 7], {n, 0, 50}] (* _G. C. Greubel_, Nov 02 2017 *)
%o A053842 (PARI) a(n) = vecsum(digits(n, 7)) % 7; \\ _Michel Marcus_, May 18 2016
%Y A053842 Cf. A010876, A053828, A141803.
%Y A053842 Cf. A010060, A053837-A053844.
%K A053842 base,nonn
%O A053842 0,3
%A A053842 _Henry Bottomley_, Mar 28 2000