Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #46 Sep 26 2017 09:26:29
%S 0,1,1,0,-2,-4,-1,-1,3,11,0,2,4,-2,-24,1,1,-3,-11,-7,41,0,-2,-4,2,24,
%T 38,-44,-1,-1,3,11,7,-41,-117,-29,0,2,4,-2,-24,-38,44,278,336,1,1,-3,
%U -11,-7,41,117,29,-527,-1199,0,-2,-4,2,24,38,-44,-278,-336,718
%N Triangle read by rows: T(n,k) = (-2)*T(n-1,k-1) + T(n,k-1) with T(2*m,0) = 0 and T(2*m+1,0) = (-1)^m.
%H Seiichi Manyama, <a href="/A292495/b292495.txt">Rows n = 0..139, flattened</a>
%F T(n+1,n)^2 + T(n,n)^2 = 5^n.
%e First few rows are:
%e 0;
%e 1, 1;
%e 0, -2, -4;
%e -1, -1, 3, 11;
%e 0, 2, 4, -2, -24;
%e 1, 1, -3, -11, -7, 41;
%e 0, -2, -4, 2, 24, 38, -44;
%e -1, -1, 3, 11, 7, -41, -117, -29;
%e 0, 2, 4, -2, -24, -38, 44, 278, 336.
%Y The diagonal of the triangle is related to A099456.
%Y The next diagonal of the triangle is related to A139011.
%Y Cf. A006495, A006496.
%Y T(n,k) = b*T(n-1,k-1) + T(n,k-1): A292789 (b=-3), this sequence (b=-2), A117918 and A228405 (b=1), A227418 (b=2), A292466 (b=4).
%K sign,tabl,look
%O 0,5
%A _Seiichi Manyama_, Sep 22 2017