A075581 - cp's OEIS frontend

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).

n	a(n)
0	1
1	4
2	16
3	80
4	448
5	2304
6	11520
7	67584
8	372736
9	1966080
10	11141120
11	63504384
12	348651520
13	1917583360
14	11142168576
15	62704844800
16	343513497600
17	1992378286080
18	11402534191104
19	63709397385216
20	361019918516224

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

cp's OEIS Frontend

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).

Table of values

List of values