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A369835
a(n) is the number of distinct values of the permanent of an n X n symmetric Toeplitz matrix using the integers 0 to n-1.
6
1, 1, 1, 6, 23, 119, 718, 5038, 40320, 362879
OFFSET
0,4
FORMULA
a(n) <= A000142(n).
MATHEMATICA
a[n_] := CountDistinct[Table[Permanent[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 A369835(n): return len({Matrix([p[i:0:-1]+p[:n-i] for i in range(n)]).per() for p in permutations(range(n))}) # Chai Wah Wu, Feb 11 2024
KEYWORD
nonn,hard,more
AUTHOR
Stefano Spezia, Feb 03 2024
STATUS
approved