(* A random effects matrix *)

REM[sigsqa_,sigsqe_,n_] := sigsqa * Outer[Times,Table[1,{n}] ,Table[1,{n}] ] +
                           sigsqe * IdentityMatrix[n]

Inverse[REM[a,b,2]]
Inverse[REM[a,b,3]]
Inverse[REM[a,b,4]]



(* My matrix,, a Pascal matrix *)

Pascal[n_] := Table[
Flatten[Join[Table[Binomial[i,j],{j,0,i}],{Table[0,{n - i}]}]],{i,0,n}]


(* Experimental and Constructive Mathematics site is

http://mosaic.cecm.sfu.ca/


Netlib is at 

http://netlib.org/

optimizer  dmnf, dmng and dmnh


Dataset is "pigment"
*)