Triangle read by rows: T(0,0)=1; for n>=1 T(n,k) is the coefficient of x^k in the monic characteristic polynomial of the n X n band matrix with main diagonal 2,3,3,..., subdiagonal -3,-3,-3,..., sub-subdiagonal 1,1,1,... and superdiagonal -1,-1,-1,... (0<=k<=n).

A124019

Triangle read by rows: T(0,0)=1; for n>=1 T(n,k) is the coefficient of x^k in the monic characteristic polynomial of the n X n band matrix with main diagonal 2,3,3,..., subdiagonal -3,-3,-3,..., sub-subdiagonal 1,1,1,... and superdiagonal -1,-1,-1,... (0<=k<=n).