A164561 Triangle with elements A120070(m,n)/A120072(m,n) read by rows, m>=2, 1<=n<m.

1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 16, 27, 4, 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 16, 1, 4, 1, 1, 1, 9, 1, 1, 9, 1, 1, 1, 16, 1, 4, 25, 16, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 27, 128, 1, 108, 1, 16, 9, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 16, 1, 4, 1, 16, 49, 4, 1, 16, 1, 4, 1, 1, 1, 27, 1

Offset

2,5

Links

Table of n, a(n) for n=2..96.

Example

The triangle starts in row m=2 as
1;
1, 1;
1, 4, 1;
1, 1, 1, 1;
1, 16, 27, 4, 1;
1, 1, 1, 1, 1, 1;
1, 4, 1, 16, 1, 4, 1;

Maple

A120070 := proc(m, n) m^2-n^2 ; end: A120072 := proc(m, n) numer(1/n^2-1/m^2) ; end:
A164561 := proc(m, n) A120070(m, n)/A120072(m, n) ; end: seq( seq(A164561(m, n), n=1..m-1), m=2..30) ; # R. J. Mathar, Aug 19 2009

Crossrefs

Sequence in context: A336870 A184101 A347176 * A178764 A070010 A293768

Adjacent sequences: A164558 A164559 A164560 * A164562 A164563 A164564

Keyword

nonn,tabl,easy

Author

Paul Curtz, Aug 16 2009

Extensions

Edited and extended by R. J. Mathar, Aug 19 2009

Status

approved