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 A374390 a(n) is the maximal permanent of an n X n symmetric Toeplitz matrix having 0 on the main diagonal and all the first n-1 primes off-diagonal. 4
 1, 0, 4, 36, 1936, 144260, 31972988, 6800311204, 2560967581304, 975834087080060, 557171087172087364 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Table of n, a(n) for n=0..10. Wikipedia, Toeplitz Matrix. EXAMPLE a(5) = 144260: [0, 7, 5, 3, 2] [7, 0, 7, 5, 3] [5, 7, 0, 7, 5] [3, 5, 7, 0, 7] [2, 3, 5, 7, 0] MATHEMATICA a[n_]:=Max[Table[Permanent[ToeplitzMatrix[Join[{0}, Part[Permutations[Prime[Range[n-1]]], i]]]], {i, (n-1)!}]]; Join[{1}, Array[a, 10]] CROSSREFS Cf. A374345. Cf. A374386, A374387, A374388, A374389. Cf. A374068 (minimal permanent). Sequence in context: A152287 A086857 A174864 * A175493 A179870 A001152 Adjacent sequences: A374387 A374388 A374389 * A374391 A374392 A374393 KEYWORD nonn,hard,more AUTHOR Stefano Spezia, Jul 07 2024 STATUS approved

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Last modified September 12 11:46 EDT 2024. Contains 375851 sequences. (Running on oeis4.)