%I #5 Jul 30 2015 22:48:09
%S 1,-2,1,-2,-2,1,-4,-2,-2,1,-10,-4,-2,-2,1,-28,-10,-4,-2,-2,1,-84,-28,
%T -10,-4,-2,-2,1,-264,-84,-28,-10,-4,-2,-2,1,-858,-264,-84,-28,-10,-4,
%U -2,-2,1,-2860,-858,-264,-84,-28,-10,-4,-2,-2,1,-9724,-2860,-858,-264,-84,-28,-10,-4,-2,-2,1,-33592,-9724,-2860,-858
%N Triangle read by rows: T(n,k) = binomial(2(n-k),n-k)/(1-2(n-k)).
%C Sequence array for expansion of sqrt(1-4x).
%C Row sums are A106191. Diagonal sums are A106192. Sequence array for A002420. Inverse of number triangle A106187.
%C Riordan array (sqrt(1-4x),x).
%e Triangle begins
%e 1;
%e -2,1;
%e -2,-2,1;
%e -4,-2,-2,1;
%e -10,-4,-2,-2,1;
%e -28,-10,-4,-2,-2,1;
%t T[n_, k_] := Binomial[2(n - k), n - k]/(1 - 2(n - k)); Flatten[ Table[ T[n, k], {n, 0, 10}, {k, 0, n}]] (* _Robert G. Wilson v_, Apr 25 2005 *)
%K easy,sign,tabl
%O 0,2
%A _Paul Barry_, Apr 24 2005
%E More terms from _Robert G. Wilson v_, Apr 25 2005