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A351019
Minimal permanent of an n X n symmetric Toeplitz matrix using the integers 1 to n.
8
1, 1, 5, 36, 480, 9991, 296913, 12099604, 637590728, 43090005714, 3550491371994, 359557627057876
OFFSET
0,3
EXAMPLE
a(3) = 36:
2 1 3
1 2 1
3 1 2
a(4) = 480:
2 1 3 4
1 2 1 3
3 1 2 1
4 3 1 2
a(5) = 9991:
3 1 2 4 5
1 3 1 2 4
2 1 3 1 2
4 2 1 3 1
5 4 2 1 3
PROG
(Python)
from itertools import permutations
from sympy import Matrix
def A351019(n): return 1 if n == 0 else min(Matrix([p[i:0:-1]+p[0:n-i] for i in range(n)]).per() for p in permutations(range(1, n+1))) # Chai Wah Wu, Jan 31 2022
CROSSREFS
Cf. A204235, A307783, A350937, A351020 (maximal).
Sequence in context: A241346 A132686 A322180 * A252782 A292194 A118018
KEYWORD
nonn,hard,more
AUTHOR
Stefano Spezia, Jan 29 2022
EXTENSIONS
a(9) from Alois P. Heinz, Jan 31 2022
a(10)-a(11) from Lucas A. Brown, Sep 06 2022
STATUS
approved