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
KEYWORD
nonn,hard,more
AUTHOR
Vladimir Reshetnikov, Mar 27 2022
STATUS
approved