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2n appears n times (n>0).
6

%I #13 Apr 21 2018 10:19:49

%S 2,4,4,6,6,6,8,8,8,8,10,10,10,10,10,12,12,12,12,12,12,14,14,14,14,14,

%T 14,14,16,16,16,16,16,16,16,16,18,18,18,18,18,18,18,18,18,20,20,20,20,

%U 20,20,20,20,20,20,22,22,22,22,22,22,22,22,22,22,22,24,24,24,24,24,24,24

%N 2n appears n times (n>0).

%C Seen as a triangle read by rows: T(n,k) = 2*n, 1<=k<=n. - _Reinhard Zumkeller_, Mar 18 2011

%H Reinhard Zumkeller, <a href="/A111650/b111650.txt">Rows n = 1..128 of triangle, flattened</a>

%t Table[Table[2n,n],{n,12}]//Flatten (* _Harvey P. Dale_, Apr 21 2018 *)

%o (Haskell)

%o a111650 n k = a111650_tabl !! (n-1) !! (k-1)

%o a111650_row n = a111650_tabl !! (n-1)

%o a111650_tabl = iterate (\xs@(x:_) -> map (+ 2) (x:xs)) [2]

%o a111650_list = concat a111650_tabl

%o -- _Reinhard Zumkeller_, Nov 14 2015, Mar 18 2011

%Y Cf. A000194, A111651, A111652.

%Y Cf. A001650, A193832.

%K easy,nonn,tabl

%O 1,1

%A _Jonathan Vos Post_, Aug 12 2005