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A074011
Number of elements of GF(5^n) with trace 1 and subtrace 2.
7
0, 2, 1, 30, 125, 600, 3150, 15625, 78000, 390625, 1952500, 9768750, 48815625, 244156250
OFFSET
1,2
COMMENTS
Same as the number of elements of GF(5^n) with trace 2 and subtrace 3. Same as the number of elements of GF(5^n) with trace 3 and subtrace 3. Same as the number of elements of GF(5^n) with trace 4 and subtrace 2.
FORMULA
(Sage)
def a(n):
ans = 0
for x in GF(5^n):
if x.charpoly().coefficients(sparse=False)[-3:-1]==[2, 1]: ans += 1
return ans # Robin Visser, Apr 26 2024
EXAMPLE
a(2;4,2)=2. Let GF(5^2) be defined by the field extension GF(5)[x]/( 2+b+b^2 ). The two elements of GF(5^2) with trace 4 and subtrace 2 are { b, 4+4b }.
KEYWORD
nonn,more
AUTHOR
Frank Ruskey and Nate Kube, Aug 19 2002
EXTENSIONS
a(8)-a(14) from Robin Visser, Apr 26 2024
STATUS
approved