%I #7 Jun 03 2019 15:34:55
%S 0,2,2,2,3,3,4,4,4,4,4,5,5,5,5,6,6,6,6,6,6,6,7,7,7,7,7,7,8,8,8,8,8,8,
%T 8,8,8,9,9,9,9,9,9,9,9,10,10,10,10,10,10,10,10,10,10,10,11,11,11,11,
%U 11,11,11,11,11,11,12,12,12,12,12,12,12,12,12,12,12,12,12
%N 2n appears 2n+1 times, 2n+1 appears 2n times.
%H Robert Israel, <a href="/A130855/b130855.txt">Table of n, a(n) for n = 0..10000</a>
%F G.f.: (1-x)^(-1)*Sum_{n>=0} (z^(2*n^2+n+1) + z^(2*n^2+3*n+1)). - _Robert Israel_, Jun 03 2019
%p seq(op([(2*n)$(2*n+1),(2*n+1)$(2*n)]),n=0..14); # _Robert Israel_, Jun 03 2019
%t Table[{PadRight[{},2n+1,2n],PadRight[{},2n,2n+1]},{n,0,10}]//Flatten (* _Harvey P. Dale_, Aug 01 2017 *)
%K nonn
%O 0,2
%A _Paul Curtz_, Jul 22 2007