12 Feb
2003
12 Feb
'03
4:51 p.m.
=RWG For how many n in {0,1,...,999999} is
n/2 + 1 2 sin(atan(sqrt(7)) n) ----------------------------- sqrt(7)
an integer? An odd integer?
=RKG Expression = 1 for n = 0, 1, 2, and hence by induction for all n ? R.
Actually of course a(0)=0. Next it does in fact go -1, -1, 1... but then ...3, 1, -5, -7, 3, 17, 11, -23, -45, 1, 91, 89, -93, -271, -85, 457, 627, -287... ...A001607 (superseeker has much more to say).