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