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A123192 Triangle read by rows: row n gives coefficients of bracket polynomial for torus knots, p(n, x) = x*p(n - 1, x) + (-1)^(n - 1)*x^(-3*n + 2), normalized. +0
1
1, 0, 0, 0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, -1, -1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, -1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, -1, -1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, -1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0 (list; graph; listen)
OFFSET

1,1

LINKS

Eric Weisstein's World of Mathematics, Torus Knot

EXAMPLE

Triangle begins:

1

0, 0, 0, 0, -1

-1, 0, 0, 0, 0, 0, 0, 0, -1

1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, -1

-1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, -1

1, 0, 0, 0, -1, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, -1

MATHEMATICA

p[0, x] = x^2; p[1, x] = -x^3; p[k_, x_] := p[k, x] = x*p[k - 1, x] + (-1)^(n - 1)*x^(-3*k + 2); w = Table[CoefficientList[x^(3*n - 2)*p[n, x], x], {n, 0, 10}]; Flatten[w]

CROSSREFS

Cf. A029694, A051764.

Sequence in context: A027356 A097080 A011746 this_sequence A089510 A138885 A014065

Adjacent sequences: A123189 A123190 A123191 this_sequence A123193 A123194 A123195

KEYWORD

tabf,sign,uned,obsc

AUTHOR

Roger Bagula (rlbagulatftn(AT)yahoo.com), Oct 03 2006

EXTENSIONS

Partially edited by njas, May 22 2007. The example lines suggest that these polynomials are really polynomials in x^4, in which case they should be rewritten in terms of y = x^4, which would remove most of the zero entries. Unforntunately the Mathematica code does not quite match the sequence.

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Last modified September 6 16:04 EDT 2008. Contains 143483 sequences.


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