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 A063431 #4 Mar 30 2012 18:51:34 %S A063431 1,1,11,1,10,111,1,2,11,1111,1,2,10,100,11111,1,2,3,11,101,111111,1,2, %T A063431 3,10,12,110,1111111,1,2,3,4,11,20,111,11111111,1,2,3,4,10,12,21,1000, %U A063431 111111111,1,2,3,4,5,11,13,22,1001,1111111111,1,2,3,4,5,10,12,20,100 %N A063431 Square array read by antidiagonals of n written in base k (n,k>0). %C A063431 It is difficult to write ten in base 11 using decimal digits. %e A063431 Rows start (1, 1, 1, 1, 1,...), (11, 10, 2, 2, 2,...), (111, 11, 10, 3, 3,...), (1111, 100, 11, 10, 4,...), etc. %Y A063431 Cf. A063432. Rows start effectively as the reverse of A001731, A001732, A001733, A001734, A001735, A001736, A008707, A008708, A008709, A008710, A008711, A008712, A008713, A008714, A008715, A008716, A008717 etc. Columns are A000042, A007088, A007089, A007090, A007091, A007092, A007093, A007094, A007095, A000027 and perhaps A055649 etc. %K A063431 base,nonn,tabl %O A063431 1,3 %A A063431 _Henry Bottomley_, Jul 20 2001