Number of ways for each of 2n (labeled) people in a circle to look at either a neighbor or the diametrally opposite person, such that no eye contact occurs.
A141221
Number of ways for each of 2n (labeled) people in a circle to look at either a neighbor or the diametrally opposite person, such that no eye contact occurs.
Terms
- a(0) =0a(1) =30a(2) =156a(3) =826a(4) =4406a(5) =23562a(6) =126104a(7) =675074a(8) =3614142a(9) =19349430a(10) =103593804a(11) =554625898a(12) =2969386478a(13) =15897666066a(14) =85113810056a(15) =455687062274
External references
- oeis: A141221