A188316 - OEIS

%I #16 Jan 17 2014 04:28:43

%S 1,0,1,1,1,1,0,3,2,1,1,3,6,3,1,0,6,10,10,4,1,1,6,20,22,15,5,1,0,10,30,

%T 49,40,21,6,1,1,10,50,91,100,65,28,7,1,0,15,70,168,216,181,98,36,8,1,

%U 1,15,105,280,444,441,301,140,45,9,1

%N Riordan array (1/(1-x^2), x/((1-x)*(1-x^2))).

%C Row sums are A077998.

%C Diagonal sums are A052547.

%C Inverse is A188317.

%F T(n,k) = T(n-1,k) + T(n-1,k-1) + T(n-2,k) - T(n-3,k), T(0,0) = T(1,1) = T(2,0) = T(2,1) = T(2,2)=1, T(1,0)=0, T(n,k)=0 if k<0 or if k>n. - _Philippe Deléham_, Jan 16 2014

%e Triangle begins

%e 1,

%e 0, 1,

%e 1, 1, 1,

%e 0, 3, 2, 1,

%e 1, 3, 6, 3, 1,

%e 0, 6, 10, 10, 4, 1,

%e 1, 6, 20, 22, 15, 5, 1,

%e 0, 10, 30, 49, 40, 21, 6, 1,

%e 1, 10, 50, 91, 100, 65, 28, 7, 1,

%e 0, 15, 70, 168, 216, 181, 98, 36, 8, 1

%K nonn,tabl

%O 0,8

%A _Paul Barry_, Mar 28 2011