The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A075613 Triangular array read by rows, giving coefficients of P(n,X) = Product_{i=1..2n+1} (X - 1/cos(Pi*k/(2n+1))), a polynomial with integer coefficients. 0
 1, 1, -4, -4, 1, 1, -12, -12, 16, 16, 1, 1, -24, -24, 80, 80, -64, -64, 1, 1, -40, -40, 240, 240, -448, -448, 256, 256, 1, 1, -60, -60, 560, 560, -1792, -1792, 2304, 2304, -1024, -1024, 1, 1, -84, -84, 1120, 1120, -5376, -5376, 11520, 11520, -11264, -11264, 4096, 4096, 1, 1, -112, -112, 2016, 2016, -13440 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Also, coefficients of U(2n,x) repeated (A008312, Chebyshev polynomials of second kind). - Ralf Stephan, Sep 06 2004 LINKS EXAMPLE P(3,X) = X^7 + X^6 - 24*X^5 - 24*X^4 + 80*X^3 + 80*X^2 - 64*X - 64. Array begins: 1, 1, -4, -4; 1, 1, -12, -12, 16, 16; 1, 1, -24, -24, 80, 80, -64, -64; ... CROSSREFS Cf. A008312, A075581. Sequence in context: A172347 A108428 A174126 * A221837 A189150 A155194 Adjacent sequences: A075610 A075611 A075612 * A075614 A075615 A075616 KEYWORD easy,sign,tabf AUTHOR Benoit Cloitre, Oct 11 2002 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified March 29 21:39 EDT 2023. Contains 361599 sequences. (Running on oeis4.)