A290511 Number of irredundant sets in the n-prism graph.

3, 9, 24, 77, 198, 522, 1550, 4477, 12732, 36214, 103579, 296294, 846303, 2417368, 6907329, 19737901, 56396602, 161138214, 460420182, 1315565162, 3758963099, 10740463083, 30688703123, 87686813998, 250547405698, 715888629491, 2045507376543, 5844625043236

Offset: 1

Author

Eric W. Weisstein, Aug 04 2017

Keywords

• nonn

Comments

The n-prism graph is well defined for n >= 3. Sequence extended to n=1 via the number of period n periodic solutions on a larger graph. - Andrew Howroyd, Aug 07 2017

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..200
• Eric Weisstein's World of Mathematics, Irredundant Set
• Eric Weisstein's World of Mathematics, Prism Graph

Crossrefs

Cf. A284702, A290336, A290493.

Formula

Empirical: a(n) = 3*a(n-1) - a(n-3) + 2*a(n-4) - 6*a(n-5) - 8*a(n-6) + 13*a(n-7) + 6*a(n-8) - 6*a(n-9) - 2*a(n-10) - 5*a(n-11) - 4*a(n-12) + 2*a(n-13) + 2*a(n-14) - a(n-15) + a(n-16) + 3*a(n-17) + 2*a(n-19) for n > 19. - Andrew Howroyd, Aug 07 2017

Extensions

a(1)-a(2) and terms a(10) and beyond from Andrew Howroyd, Aug 07 2017