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

0,2

Links

Table of n, a(n) for n=0..20.

Example

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.

Crossrefs

Sequence in context: A106568 A183146 A160564 * A171454 A316944 A020080

Adjacent sequences: A075578 A075579 A075580 * A075582 A075583 A075584

Keyword

easy,nonn

Author

Benoit Cloitre, Oct 11 2002

Status

approved