|
|
A014610
|
|
Tetranacci numbers arising in connection with current algebras sp(2)_n.
|
|
1
|
|
|
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
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
LINKS
|
|
|
FORMULA
|
G.f.: (3+2x+2x^2+x^3)/(1-x-x^2-x^3-x^4).
|
|
MATHEMATICA
|
|
|
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
|
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|