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 A141803 #18 Jun 18 2018 15:48:37
%S A141803 1,1,1,1,2,0,1,2,1,1,1,2,3,2,0,1,2,3,1,0,0,1,2,3,4,2,2,1,1,2,3,4,1,3,
%T A141803 0,1,1,2,3,4,5,2,0,1,0,1,2,3,4,5,1,3,2,1,0,1,2,3,4,5,6,2,4,3,2,1,1,2,
%U A141803 3,4,5,6,1,3,0,0,0,0,1,2,3,4,5,6,7,2,4,2,1,2,1,1,2,3,4,5,6,7,1,3,5,3,3,0,1
%N A141803 Triangle read by rows derived from generalized Thue-Morse sequences.
%C A141803 Triangle read by rows, antidiagonals of an array composed of generalized Thue-Morse sequences [defined in A010060, comment of Zizka]. For each row of the array, n>0; n-th term of m-th row (m>0) = sum of digits of n in base (m+1), mod (m+1).
%C A141803 Every row of the array starting from the n-th one as well as every row of the triangle starting from the (2*n-1)-th one begins from (1,2,3,...,n).
%C A141803 Row sums = A141804: (1, 2, 3, 5, 8, 7, 15, 15, 18, 22,...).
%C A141803 Row 1 of the array (corresponding to base 2) = A010060 (n>0), rows 2 - 8 are the sequences A053838 - A053844, row 9 = A053837.
%H A141803 Ivan Neretin, <a href="/A141803/b141803.txt">Table of n, a(n) for n = 1..8001</a>
%e A141803 First few rows of the array are:
%e A141803 1, 1, 0, 1, 0, 0, 1, 1,...
%e A141803 1, 2, 1, 2, 0, 2, 0, 1,...
%e A141803 1, 2, 3, 1, 2, 3, 0, 2,...
%e A141803 1, 2, 3, 4, 1, 2, 3, 4,...
%e A141803 1, 2, 3, 4, 5, 1, 2, 3,...
%e A141803 1, 2, 3, 4, 5, 6, 1, 2,...
%e A141803 ...
%e A141803 Triangle = antidiagonals of the array:
%e A141803 1;
%e A141803 1, 1;
%e A141803 1, 2, 0;
%e A141803 1, 2, 1, 1;
%e A141803 1, 2, 3, 2, 0;
%e A141803 1, 2, 3, 1, 0, 0;
%e A141803 1, 2, 3, 4, 2, 2, 1;
%e A141803 1, 2, 3, 4, 1, 3, 0, 1;
%e A141803 1, 2, 3, 4, 5, 2, 0, 1, 0;
%e A141803 1, 2, 3, 4, 5, 1, 3, 2, 1, 0;
%e A141803 1, 2, 3, 4, 5, 6, 2, 4, 3, 2, 1;
%e A141803 1, 2, 3, 4, 5, 6, 1, 3, 0, 0, 0, 0;
%e A141803 1, 2, 3, 4, 5, 6, 7, 2, 4, 2, 1, 2, 1;
%e A141803 1, 2, 3, 4, 5, 6, 7, 1, 3, 5, 3, 3, 0, 1;
%e A141803 ...
%e A141803 a(8) = 2, = (3,2) of the array indicating that in the sequence 1,2,3,...mod 4, sum of digits of "2" mod 4 = 2.
%t A141803 Flatten@Table[Mod[Total@IntegerDigits[n - i, i], i], {n, 16}, {i, n - 1, 2, -1}] (* _Ivan Neretin_, Jun 18 2018 *)
%Y A141803 Cf. A010060, A053837 - A053844, A141804.
%K A141803 nonn,tabl
%O A141803 1,5
%A A141803 _Gary W. Adamson_ and _Roger L. Bagula_, Jul 06 2008
%E A141803 Explanation in the Comments section corrected by _Andrey Zabolotskiy_, May 18 2016