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.

A125794 Column 4 of table A125790; also equals row sums of matrix power A078121^4.

Original entry on oeis.org

1, 5, 25, 165, 1625, 25509, 664665, 29559717, 2290267225, 314039061413, 77160820913241, 34317392762489765, 27859502236825957465, 41575811106337540656037, 114746581654195790543205465, 588765612737696531880325270437, 5642056933026209681424588087899225
Offset: 0

Views

Author

Paul D. Hanna, Dec 10 2006

Keywords

Comments

Triangle A078121 shifts left one column under matrix square and is related to partitions into powers of 2.

Crossrefs

A diagonal of A152977.

Programs

  • PARI
    a(n)=local(p=4,q=2,A=Mat(1), B); for(m=1, n+1, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i || j==1, B[i, j]=1, B[i, j]=(A^q)[i-1, j-1]); )); A=B); return(sum(c=0,n,(A^p)[n+1,c+1]))