OFFSET
1,2
COMMENTS
The sequence of connected Dynkin diagrams proceeds as {A1}, {A2, B2, G2}, {A3, B3, C3}, {A4, B4, F4, C4, D4}, {A5, B5, C5, D5}, {A6, B6, C6, D6, E6}, {A7, B7, C7, D7, E7}, {A8, B8, C8, D8, E8}, {A9, B9, C9, D9}, ...
REFERENCES
R. W. Carter, Simple groups of Lie type. Vol. 22, John Wiley & Sons, 1989, p. 40.
LINKS
Wikipedia, Dynkin diagram
Index entries for linear recurrences with constant coefficients, signature (1).
FORMULA
a(n) = 4 for n > 8.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Simon Burton, Jan 18 2023
EXTENSIONS
a(9) corrected by Andrey Zabolotskiy, Jul 23 2024
STATUS
approved