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URL: https://oeis.org/A390884

⇱ A390884 - OEIS


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A390884
a(n) is the permanent of the n X n matrix M(n) whose generic entry M(i, j, n) is F(2*n - (i + j)) with 1 <= i,j <= n and F = A000045.
2
1, 0, 1, 8, 276, 29340, 9861600, 10045401600, 30570226194816, 273397821409480320, 7104028561281623160000, 531056736481785504007248000, 113298939677963776783311231482880, 68516740194104115461776815173961400320, 116769911106116708653768530961178427783091200, 558013528500458437166237588824657715740173004800000
OFFSET
0,4
COMMENTS
Except for n = 2 corresponding to the Cassini's identity F(2)*F(0) - F(1)^2 = -1 = det(M(2)), the matrix M(n) is singular.
EXAMPLE
a(4) = 276:
[8, 5, 3, 2]
[5, 3, 2, 1]
[3, 2, 1, 1]
[2, 1, 1, 0]
MATHEMATICA
a[n_]:=Permanent[Table[Fibonacci[2n-(i+j)], {i, n}, {j, n}]]; Join[{1}, Array[a, 15]]
PROG
(PARI) apply( {A390884(n)=matpermanent(matrix(n, n, i, j, fibonacci(2*n-i-j)))}, [0..20]) \\ M. F. Hasler, Nov 22 2025
CROSSREFS
KEYWORD
nonn
AUTHOR
Stefano Spezia, Nov 22 2025
STATUS
approved