OFFSET
1,1
LINKS
Eric M. Schmidt, Table of n, a(n) for n = 1..1000
Frank Luebeck, Numbers of Conjugacy Classes in Finite Groups of Lie Type.
FORMULA
Let q be the n-th prime power.
a(n) = q^4 + 2q^3 + 6q^2 + 10q + 19 if q == 0 mod 2.
a(n) = q^4 + 2q^3 + 7q^2 + 15q + 30 if q == 0 mod 3.
a(n) = q^4 + 2q^3 + 7q^2 + 15q + 31 otherwise.
PROG
(Sage) def A225931(q) : return q^4 + 2*q^3 + (6*q^2 + 10*q + 19 if q%2==0 else 7*q^2 + 15*q + 30 if q%3==0 else 7*q^2 + 15*q + 31)
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric M. Schmidt, May 21 2013
STATUS
approved