0,3

How does a(n+1)/a(n) behave as n increases?

Table of n, a(n) for n=0..17.

David A. Corneth, Illustration for a(4)

a(3) = 2 because {(1,3), (2,5), (4,6)} and {(1,5), (2,3), (4,6)} are corresponding sets.

a(4) = 7 because {(1,6), (2,5), (3,8), (4,7)}, {(1,3), (2,7), (4,6), (5,8)}, {(1,7), (2,3), (4,6), (5,8)}, {(1,3), (2,5), (4,7), (6,8)}, {(1,5), (2,3), (4,7), (6,8)}, {(1,2), (3,7), (4,6), (5,8)}, {(1,2), (3,8), (4,7), (5,6)} are corresponding sets.

Cf. A002968, A060963, A272363, A320129.

Sequence in context: A005298 A063692 A292615 * A123209 A123604 A321306

Adjacent sequences: A320165 A320166 A320167 * A320169 A320170 A320171

nonn,more

Altug Alkan, Oct 07 2018

a(13)-a(17) from Rémy Sigrist, Oct 07 2018

approved