A075581 Let P(n,X) = Product_{i=1..2n+1} (X - 1/cos(Pi*k/(2n+1))); then P(n,X) is a polynomial with integer coefficients. Sequences gives maximum values of absolute values of coefficients of P(n,X).

1, 4, 16, 80, 448, 2304, 11520, 67584, 372736, 1966080, 11141120, 63504384, 348651520, 1917583360, 11142168576, 62704844800, 343513497600, 1992378286080, 11402534191104, 63709397385216, 361019918516224

Offset: 0

Author

Benoit Cloitre, Oct 11 2002

Keywords

• easy
• nonn

Examples

			P(3,X) = X^7 + X^6 - 24*X^5 - 24*X^4 + 80*X^3 + 80*X^2 - 64*X - 64, hence a(3) = 80.