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 A167407 #10 Nov 01 2021 03:13:21
%S A167407 0,-1,1,-2,1,1,-3,1,1,1,-4,1,1,1,1,-5,1,1,1,1,1,-6,1,1,1,1,1,1,-7,1,1,
%T A167407 1,1,1,1,1,-8,1,1,1,1,1,1,1,1,-9,1,1,1,1,1,1,1,1,1,-10,1,1,1,1,1,1,1,
%U A167407 1,1,1,-11,1,1,1,1,1,1,1,1,1,1,1,-12,1,1,1,1,1,1,1,1,1,1,1,1,-13,1,1,1,1,1
%N A167407 T(m,n) is -m if n=0, 1 elsewhere.
%C A167407 This triangle encodes a family of conditionally convergent series for the logarithm of positive integers, according to: log(m)=Sum_{n>0} T(m-1,n mod m)/n.
%C A167407 The second row of the triangle, m=1, corresponds to Mercator's series:
%C A167407 log(2)=1-1/2+1/3-1/4+1/5-1/6+-...
%e A167407 Triangle begins:
%e A167407 0;
%e A167407 -1,1;
%e A167407 -2,1,1;
%e A167407 -3,1,1,1;
%e A167407 -4,1,1,1,1;
%e A167407 ...
%t A167407 Flatten[Table[{-n,Table[1,{n}]},{n,0,15}]] (* _Harvey P. Dale_, Apr 17 2015 *)
%Y A167407 Cf. A061347, A166711, A166871.
%K A167407 sign,tabl
%O A167407 0,4
%A A167407 _Jaume Oliver Lafont_, Nov 03 2009, Nov 04 2009
%E A167407 Revised by _Jaume Oliver Lafont_, Nov 11 2009