0,2

A113387 equals the matrix cube of A113381, which has the property: column k of A113381^3 = column 0 of A113389^(3*k+2) for k>=0.

(PARI) {a(n)=local(A, B); A=Mat(1); for(m=2, n+1, B=matrix(m, m); for(i=1, m, for(j=1, i, if(i<3|j==i|j>m-1, B[i, j]=1, if(j==1, B[i, 1]=1, B[i, j]=(A^(3*j-2))[i-j+1, 1])); )); A=B); (matrix(#A, #A, r, c, if(r>=c, (A^(3*c-1))[r-c+1, 1]))^3)[n+1, 1]}

Cf. A113381, A113387, A113389.

Sequence in context: A153467 A052731 A052711 this_sequence A113393 A138426 A108092

Adjacent sequences: A113385 A113386 A113387 this_sequence A113389 A113390 A113391

nonn

Paul D. Hanna (pauldhanna(AT)juno.com), Nov 14 2005