%I
%S 1,1,1,2,3,1,7,12,6,1,41,73,41,10,1,376,675,390,105,15,1,
%T 5033,9048,5256,1446,225,21,1,92821,166901,97034,26796,4242,427,
%U 28,1,2257166,4058703,2359939,652054,103515,10570,742,36,1,69981919,125837748,73169550,20218251,3210939
%N Triangle, read by rows, equal to the matrix inverse of A056241, which is formed from the evenindexed trinomial coefficients.
%C Column 0 forms signed Hammersley's polynomial p_n(1) (A006846). Column 1 forms A104028.
%C Triangle T(n,k), 0<=k<=n, read by rows, given by [ 1, 1, 3, 4, 7, 9, 13, 16, 21, ...] DELTA [1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, ...] where DELTA is the operator defined in A084938; see A004652 : 0, 1, 1, 3, 4, 7, 9, 13, ...  _Philippe DelĂ©ham_, Sep 26 2005
%e Rows begin:
%e 1;
%e 1,1;
%e 2,3,1;
%e 7,12,6,1;
%e 41,73,41,10,1;
%e 376,675,390,105,15,1;
%e 5033,9048,5256,1446,225,21,1;
%e 92821,166901,97034,26796,4242,427,28,1;
%e 2257166,4058703,2359939,652054,103515,10570,742,36,1; ...
%o (PARI) T(n,k)=if(n<k  k<0, 0, ((matrix(n+2,n+2,m,j, if(m && gt;=j,polcoeff((1+x+x^2)^(m1)+O(x^(2*j)),2*j2))))^1)[n+1,k+1])
%Y Cf. A056241, A104028, A027907.
%K sign,tabl
%O 0,4
%A _Paul D. Hanna_, Feb 26 2005
