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 A201208 #25 Mar 15 2023 14:03:05
%S A201208 1,2,2,1,1,1,2,2,2,2,1,1,1,1,1,2,2,2,2,2,2,1,1,1,1,1,1,1,2,2,2,2,2,2,
%T A201208 2,2,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,2,2,
%U A201208 2,2,2,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2
%N A201208 One 1, two 2's, three 1's, four 2's, five 1's, ...
%F A201208 a(n) = A057212(n) + 1. - _T. D. Noe_, Nov 28 2011
%e A201208 May be written as a triangle:
%e A201208 1
%e A201208 2 2
%e A201208 1 1 1
%e A201208 2 2 2 2
%e A201208 1 1 1 1 1
%e A201208 2 2 2 2 2 2
%e A201208 1 1 1 1 1 1 1
%e A201208 Row sums are A022998(n+1).
%t A201208 ReplaceAll[ColumnForm[Table[Mod[k, 2], {k, 12}, {n, k}], Center], 0 -> 2] (* _Alonso del Arte_, Nov 28 2011 *)
%o A201208 (Haskell)
%o A201208 a201208 n = a201208_list !! (n-1)
%o A201208 a201208_list = concat $ zipWith ($) (map replicate [1..]) a000034_list
%o A201208 -- _Reinhard Zumkeller_, Dec 02 2011
%Y A201208 Cf. A057212, A022998.
%Y A201208 Cf. A000034.
%K A201208 nonn,tabl,easy
%O A201208 1,2
%A A201208 _Paul Curtz_, Nov 28 2011
%E A201208 Edited by _N. J. A. Sloane_, Dec 02 2011