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

1, 12, 186, 3892, 106089, 3620379, 149740555, 7316974618, 413939637263, 26674140920951, 1932099681055593, 155591826253029963, 13802736990317399904, 1338361705725008068468, 140897444878639681727527, 16011627854373788685284865, 1954208195019902817905605773, 255019192486460947257880420210

Offset

0,2

Links

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

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) = my(A, B); A=Mat(1); for(m=2, n+2, 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+2, 2]}
for(n=0, 20, print1(a(n), ", ")) \\ program revised by Paul D. Hanna, May 23 2026

Crossrefs

Cf. A113392, A113389, A113381, A113388.

Sequence in context: A202632 A385669 A285410 * A218886 A239294 A294409

Adjacent sequences: A113390 A113391 A113392 * A113394 A113395 A113396

Keyword

nonn

Author

Paul D. Hanna, Nov 14 2005

Extensions

The terms were corrected at the suggestion of R. J. Mathar. - Paul D. Hanna, May 23 2026

Status

approved