A113393 Column 1 of triangle A113392, also equals column 0 of A113381^6.

1, 6, 48, 605, 11196, 280440, 8981460, 353283128, 16567072675, 905357065354, 56632746126107, 3997082539456084, 314584709388906568, 27340439653453247728, 2602372304420672868499, 269388182085308601450047

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Formula

A113392 equals the matrix square of A113389, which has the property: Column k of A113389^2 = column 0 of A113381^(3*k+3) for k>=0.

Prog

(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))[r-c+1, 1]))^2)[n+1, 1]

Crossrefs

Cf. A113392, A113389, A113381, A113388 (column 0).

Sequence in context: A052731 A052711 A113388 * A138426 A291104 A108092

Adjacent sequences: A113390 A113391 A113392 * A113394 A113395 A113396

Keyword

nonn

Author

Paul D. Hanna, Nov 14 2005

Status

approved