OFFSET
0,12
FORMULA
EXAMPLE
Trivially, for n = 0,1 no pairs are possible so a(0) and a(1) are 0.
For n = 2, the expectation, E(n), equals 0.5. So a(2) = floor(E(2)) - floor(E(1)) - floor(E(1)) = 0.
For n = 5 = 2 + 3, E(5) = 20/13, E(2) = 0.5 and E(3) = 0.75 and a(5) = floor(E(5)) - floor(E(2)) - floor(E(3)) = 1.
Interestingly, for n = 8, E(8) = 532/191 and E(4) = 6/5, so a(n) = 2 - 1 - 1 = 0.
CROSSREFS
KEYWORD
nonn
AUTHOR
Rajan Murthy, Jun 12 2014
STATUS
approved