OFFSET
1,2
EXAMPLE
a(7) = -3384288*cos(Pi/7) - 3460896*sin(Pi/14) - 45888*cos(2*Pi/7) - 28224*cos(15*Pi/7) + 48384*cos(17*Pi/7) + 1706400 + 3458400*sin(3*Pi/14) = 144. - Chai Wah Wu, Sep 19 2021
PROG
(PARI) P(n)=matpermanent(matrix(n, n, j, k, cos((Pi*j*k)/n)));
for(k=1, 25, print1(round(2^(k-1)*P(k)^2), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Hugo Pfoertner, Sep 18 2021
STATUS
approved