OFFSET
1,1
FORMULA
G.f.: x(2x^3+2x^2+6x+4)/(1-x^3)^2.
MAPLE
B := (n, m) -> lcm(n, m)/n + lcm(n, m)/m - 1: seq(B(m+3, m), m=1..90);
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Asher Auel, Dec 15 2000
STATUS
approved