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

Author

Noureddine Chair

Keywords

• easy
• nonn

Links

• 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).

Programs

Mathematica

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

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

Formula

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