A014610 Tetranacci numbers arising in connection with current algebras sp(2)_n.

3, 5, 10, 19, 37, 71, 137, 264, 509, 981, 1891, 3645, 7026, 13543, 26105, 50319, 96993, 186960, 360377, 694649, 1338979, 2580965, 4974970, 9589563, 18484477, 35629975, 68678985, 132383000, 255176437, 491868397, 948106819, 1827534653, 3522686306, 6790196175

Offset

0,1

Links

Table of n, a(n) for n=0..33.

Noureddine Chair, Grassmannian Cohomology Rings and Fusion Rings From Algebraic Equations, arXiv:hep-th/9704138, 1997.

Index entries for linear recurrences with constant coefficients, signature (1,1,1,1).

Formula

G.f.: (3+2x+2x^2+x^3)/(1-x-x^2-x^3-x^4).

Mathematica

LinearRecurrence[{1, 1, 1, 1}, {3, 5, 10, 19}, 29] (* Jean-François Alcover, Feb 24 2019 *)

Prog

(PARI) my(p=Mod('x, 'x^4-'x^3-'x^2-'x-1)); a(n) = -subst(lift(p^(n+7)), 'x, -1); \\ Kevin Ryde, May 03 2021

Crossrefs

Sequence in context: A158943 A133999 A238431 * A117591 A003055 A317766

Adjacent sequences: A014607 A014608 A014609 * A014611 A014612 A014613

Keyword

easy,nonn

Author

Noureddine Chair

Status

approved