OFFSET
1,2
EXAMPLE
Taking x=1, y=2 gives 2 * 6 =12
MATHEMATICA
bipr[{a_, b_}]:=a(a+1)b(b+1); Take[Union[bipr/@Subsets[Range[0, 40], {2}]], 50] (* Harvey P. Dale, Jun 01 2012 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Stuart M. Ellerstein (ellerstein(AT)aol.com), Apr 04 2000
EXTENSIONS
More terms from James A. Sellers, Apr 22 2000
STATUS
approved