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Triangle read by rows: row n consists of 0 followed by n (n+1)'s with alternating signs.
2

%I #11 Nov 10 2023 03:44:49

%S 0,0,-2,0,-3,3,0,-4,4,-4,0,-5,5,-5,5,0,-6,6,-6,6,-6,0,-7,7,-7,7,-7,7,

%T 0,-8,8,-8,8,-8,8,-8,0,-9,9,-9,9,-9,9,-9,9,0,-10,10,-10,10,-10,10,-10,

%U 10,-10

%N Triangle read by rows: row n consists of 0 followed by n (n+1)'s with alternating signs.

%H Paolo Xausa, <a href="/A138057/b138057.txt">Table of n, a(n) for n = 0..1325</a> (rows 0..50 of the triangle, flattened).

%F T(n,k) = [k>0]*(n+1)*(-1)^k, with n >= 0 and 0 <= k <= n, where [] is the Iverson bracket. - _Paolo Xausa_, Nov 10 2023

%e From _Paolo Xausa_, Nov 10 2023: (Start)

%e Triangle begins:

%e n\k| 0 1 2 3 4 ...

%e ---+---------------------

%e 0 | 0;

%e 1 | 0, -2;

%e 2 | 0, -3, 3;

%e 3 | 0, -4, 4, -4;

%e 4 | 0, -5, 5, -5, 5;

%e ... (End)

%t Array[Join[{0},(-1)^Range[#](#+1)]&,15,0] (* _Paolo Xausa_, Nov 10 2023 *)

%Y Cf. A131738.

%K tabl,sign

%O 0,3

%A _Paul Curtz_, May 02 2008