A113386 - OEIS

A113386

Column 1 of triangle A113384, also equals column 0 of A113381^5.

1, 10, 130, 2365, 57695, 1798275, 68931064, 3155772612, 168671241316, 10336797449013, 715846906453760, 55355481111622706, 4732541017570608210, 443593124488673026361, 45261577596891190335258

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..14.

FORMULA

A113384 equals the matrix square of A113381, which has the property: column k of A113381^2 = column 0 of A113381^(3*k+2) for k>=0.

PROG

(PARI) a(n)=local(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-1))[r-c+1, 1]))^2)[n+2, 2]

CROSSREFS

Cf. A113381, A113384, A113385 (column 0).

Sequence in context: A355422 A051607 A292119 * A302615 A281395 A268786

Adjacent sequences: A113383 A113384 A113385 * A113387 A113388 A113389

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Nov 14 2005

STATUS

approved