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.

A144966 Square array T(n,k) read by antidiagonals up. A055615 interleaved with k-1 zeros in each column. Redheffer type matrix.

Original entry on oeis.org

1, -2, 1, -3, 1, 1, 0, 0, 0, 1, -5, -2, 1, 0, 1, 6, 0, 0, 0, 0, 1, -7, -3, 0, 1, 0, 0, 1, 0, 0, -2, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 10, 0, 0, 0, 0, 0, 0, 0, 0, 1, -11, -5, -3, -2, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -13, 6, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 14, 0, 0, 0, -2, 0
Offset: 1

Views

Author

Mats Granvik, Sep 27 2008

Keywords

Comments

Determinant of this array appears to be the triangular numbers. The number of permutations that contribute to the result of the zero corner determinant that give the natural numbers, appears to be given by A002033.

Examples

			Determinant of:
1
is equal to 1.
Determinant of:
1,1
-2,0
is equal to 2.
Determinant of:
1,1,1
-2,1,0
-3,0,0
is equal to 3.
Determinant of:
1,1,1,1
-2,1,0,0
-3,0,1,0
0,-2,0,0
is equal to 4.
Determinant of:
1,1,1,1,1
-2,1,0,0,0
-3,0,1,0,0
0,-2,0,1,0
-5,0,0,0,0
is equal to 5.
Determinant of:
1,1,1,1,1,1
-2,1,0,0,0,0
-3,0,1,0,0,0
0,-2,0,1,0,0
-5,0,0,0,1,0
6,-3,-2,0,0,0
is equal to 6.
		

Crossrefs

Programs

  • Excel
    =if(mod(row(); column())=0; lookup(row()/column(); A000027; A055615); if(row()=1; 1; 0))