A113356 Column 0 of triangle A113355, which is the matrix square of A113350.

1, 4, 18, 112, 965, 10957, 156699, 2727793, 56306695, 1350043964, 36979531548, 1141573025171, 39272377323692, 1491452150268435, 62027842189908230, 2805631215820328991, 137199563717151509076, 7215932308408758314446

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Formula

a(n) = A113346(n+1) - 1, where A113346 equals column 0 of triangle A113345 (=A113340^2).

Prog

(PARI) a(n)=local(A, B); A=matrix(1, 1); A[1, 1]=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^(2*j-1))[i-j+1, 1])); )); A=B); (matrix(#A, #A, r, c, if(r>=c, (A^(2*c))[r-c+1, 1]))^2)[n+1, 1]

Crossrefs

Cf. A113340, A113350, A113355, A113357 (column 1), A113358 (column 2), A113359 (column 3).

Sequence in context: A364623 A143920 A233534 * A062805 A326093 A222584

Adjacent sequences: A113353 A113354 A113355 * A113357 A113358 A113359

Keyword

nonn

Author

Paul D. Hanna, Nov 08 2005

Status

approved