A377769 Number of edge cuts in the n-Plummer-Toft graph.

314, 2430, 19538, 159806, 1316946, 10879134, 89853810, 741053950, 6099643154, 50099413854, 410626550450, 3358899990206, 27425013503058, 223544362076190, 1819336077737970, 14786154478432126, 120017920267627922, 973050998951150814, 7880772707278994738

Offset

1,1

Links

Christian Sievers, Table of n, a(n) for n = 1..1105

Eric Weisstein's World of Mathematics, Edge Cut.

Eric Weisstein's World of Mathematics, Plummer-Toft Graph.

Index entries for linear recurrences with constant coefficients, signature (21,-150,404,-296,64).

Formula

G.f.: x*(314 - 4164*x + 15608*x^2 - 12848*x^3 + 2944*x^4)/((1 - 8*x)*(1 - 5*x + 2*x^2)*(1 - 8*x + 4*x^2)). - Andrew Howroyd, Dec 09 2024, after Christian Sievers

Prog

(PARI) a(n)=64*8^n-([18, 9, 11, 5]*[7, 0, 1, 0; 1, 1, 0, 1; 3, 0, 1, 0; 6, 2, 0, 4]^n)[1] \\ Christian Sievers, Dec 09 2024

Crossrefs

Cf. A378848.

Sequence in context: A050807 A157621 A230945 * A183691 A284078 A231021

Adjacent sequences: A377766 A377767 A377768 * A377770 A377771 A377772

Keyword

nonn,easy

Author

Eric W. Weisstein, Nov 06 2024

Extensions

a(7) from Eric W. Weisstein, Nov 17 2024

a(8) and beyond from Christian Sievers, Dec 09 2024

Status

approved