cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A113377 Column 2 of triangle A113374, also equals column 0 of A113381^7.

Original entry on oeis.org

1, 14, 252, 5957, 179270, 6641502, 294524076, 15285260326, 911664081027, 61573228385424, 4652227417900405, 389256081747220268, 35759870451009454561, 3580704593280285017869, 388344720309998846243731
Offset: 0

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Author

Paul D. Hanna, Nov 14 2005

Keywords

Crossrefs

Cf. A113374, A113375 (column 0), A113376 (column 1).

Programs

  • PARI
    a(n)=local(A,B);A=Mat(1);for(m=2,n+3,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);(A^2)[n+3,3]

Formula

A113374 equals the matrix square of A113370, which has the property: column k of A113370^2 = column 0 of A113381^(3*k+1) for k>=0.