A360198 Number of induced cycles in the 5 X n grid graph.

0, 4, 14, 58, 229, 749, 2180, 6188, 17912, 52620, 154383, 450195, 1309452, 3811888, 11110432, 32392550, 94412963, 275116777, 801676752, 2336222946, 6808405238, 19841419978, 57821971765, 168504312515, 491055599116, 1431039769316, 4170353383134, 12153282490316, 35417189532323

Offset

1,2

Links

Andrew Howroyd, Table of n, a(n) for n = 1..200

Index entries for linear recurrences with constant coefficients, signature (6,-14,17,-3,-17,16,-2,9,-27,5,19,-3,-2,-5,2).

Formula

G.f.: x^2*(4 - 10*x + 30*x^2 + 9*x^3 - 39*x^4 + 16*x^5 + 49*x^6 + 28*x^7 - 76*x^8 - 58*x^9 + 7*x^10 + 13*x^11 + 9*x^12 - 4*x^13)/((1 - x)^2*(1 - 4*x + 5*x^2 - 3*x^3 - 8*x^4 + 4*x^5 - 2*x^7 - 13*x^8 + 3*x^9 + 14*x^10 + 6*x^11 + x^12 - 2*x^13)).

Crossrefs

Row 5 of A360196.

Sequence in context: A325929 A134826 A096242 * A296943 A104987 A149492

Adjacent sequences: A360195 A360196 A360197 * A360199 A360200 A360201

Keyword

nonn,easy

Author

Andrew Howroyd, Jan 29 2023

Extensions

Missing a(1)=0 inserted by Andrew Howroyd, Feb 23 2023

Status

approved