OFFSET
1,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..500
Eric Weisstein's World of Mathematics, Edge Cut.
Eric Weisstein's World of Mathematics, Ladder Graph.
Index entries for linear recurrences with constant coefficients, signature (13,-42,16).
FORMULA
MATHEMATICA
LinearRecurrence[{13, -42, 16}, {1, 11, 105}, 25] (* Paolo Xausa, Jun 24 2024 *)
Table[2^(3 n - 2) + (((5 - Sqrt[17])/2)^n - ((5 + Sqrt[17])/2)^n)/Sqrt[17], {n, 20}] // Expand (* Eric W. Weisstein, Nov 03 2024 *)
CoefficientList[Series[-(1 - 2 x + 4 x^2)/((-1 + 8 x) (1 - 5 x + 2 x^2)), {x, 0, 20}], x] (* Eric W. Weisstein, Nov 03 2024 *)
PROG
(PARI) Vec((1 - 2*x + 4*x^2)/((1 - 8*x)*(1 - 5*x + 2*x^2)) + O(x^25))
CROSSREFS
KEYWORD
nonn,easy,changed
AUTHOR
Andrew Howroyd, Jan 28 2023
STATUS
approved