OFFSET
1,2
COMMENTS
Same as the number of elements of GF(3^n) with trace 2 and subtrace 2.
LINKS
EXAMPLE
a(2;1,2)=2. Let GF(3^2) be defined by the field extension GF(3)[x]/( 2+b+b^2 ). The two elements of GF(3^2) with trace 1 and subtrace 2 are { 1+b, 2b }.
PROG
(SageMath)
d = {(0, 0): [1], (0, 1): [0], (0, 2): [0], (1, 0): [1], (1, 1): [0], (1, 2): [0], (2, 0): [1], (2, 1): [0], (2, 2): [0]}
for n in (2..9):
for a in d.values(): a.append(0)
k.<u> = GF((3, n))
for x in k:
d[(x.trace(), x.charpoly().list()[-3])][-1] += 1
print(d[(1, 2)]) # Andrey Zabolotskiy, Nov 07 2024
CROSSREFS
KEYWORD
nonn,more,changed
AUTHOR
Frank Ruskey and Nate Kube, Aug 19 2002
EXTENSIONS
a(9) and a(14)-a(15) corrected, unverified terms a(17)-a(20) removed. Based on the original Data in A074000-A074005, a(17)-a(20) are possibly equal to 14351094, 43046721, 129146724, 387400806. - Andrey Zabolotskiy, Nov 07 2024
STATUS
approved