login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A369834
a(n) is the number of distinct values of the determinant of an n X n symmetric Toeplitz matrix using the integers 0 to n-1.
7
1, 1, 2, 5, 23, 94, 614, 4628, 38243, 351024
OFFSET
0,3
FORMULA
a(n) <= A000142(n).
MATHEMATICA
a[n_] := CountDistinct[Table[Det[ToeplitzMatrix[Part[Permutations[Join[{0}, Range[n - 1]]], i]]], {i, n !}]]; Join[{1}, Array[a, 9]]
PROG
(Python)
from itertools import permutations
from sympy import Matrix
def A369834(n): return len({Matrix([p[i:0:-1]+p[:n-i] for i in range(n)]).det() for p in permutations(range(n))}) # Chai Wah Wu, Feb 11 2024
KEYWORD
nonn,hard,more
AUTHOR
Stefano Spezia, Feb 03 2024
STATUS
approved