my @poly_coeffs = (0) x ($n + 1) ;
$poly_coeffs[0]++ ;
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Do you see something else/shorter/better ?

shorter?

my @poly_coeffs = map !$_+0, 0..$n;
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better? (and even shorter)

my @poly_coeffs = (1, (0) x $n);
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but I just had to include a map based solution... ;-)