A164561 - OEIS

%I #4 Mar 31 2012 08:58:36

%S 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,

%T 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,

%U 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

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

%e The triangle starts in row m=2 as

%e 1;

%e 1, 1;

%e 1, 4, 1;

%e 1, 1, 1, 1;

%e 1, 16, 27, 4, 1;

%e 1, 1, 1, 1, 1, 1;

%e 1, 4, 1, 16, 1, 4, 1;

%p A120070 := proc(m,n) m^2-n^2 ; end: A120072 := proc(m,n) numer(1/n^2-1/m^2) ; end:

%p 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

%K nonn,tabl,easy

%O 2,5

%A _Paul Curtz_, Aug 16 2009

%E Edited and extended by _R. J. Mathar_, Aug 19 2009