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A350711
The number of different values taken by the determinant of a square n X n matrix whose elements are 1 or i = sqrt(-1).
0
1, 2, 7, 11, 27, 63, 177
OFFSET
0,2
EXAMPLE
For n = 2 there are 2^(2*2) = A002416(2) = 16 square 2 X 2 matrices whose elements are 1 or i. Their determinants take 7 distinct values: 0, 2, -2, 1 + i, 1 - i, -1 + i, -1 - i. So a(2) = 7.
MATHEMATICA
Join[{1, 2}, Table[With[{d = Union[Det /@ DeleteCases[Subsets[Tuples[{1, I}, n], {n}], {{__, 1}, __, {I, __} | {__, I}}]]}, Length[Union[d, -d, {0}]]], {n, 2, 6}]]
CROSSREFS
Sequence in context: A024857 A024481 A024591 * A309465 A309466 A309467
KEYWORD
nonn,hard,more
AUTHOR
STATUS
approved