cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A008312 Triangle of coefficients of Chebyshev polynomials U_n(x).

Original entry on oeis.org

1, 2, -1, 4, -4, 8, 1, -12, 16, 6, -32, 32, -1, 24, -80, 64, -8, 80, -192, 128, 1, -40, 240, -448, 256, 10, -160, 672, -1024, 512, -1, 60, -560, 1792, -2304, 1024, -12, 280, -1792, 4608, -5120, 2048
Offset: 0

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Comments

Version with zeros in A053117. - Philippe Deléham, Nov 27 2013

Examples

			From _Philippe Deléham_, Nov 27 2013: (Start)
Triangle begins:
    1;
    2;
   -1,    4;
   -4,    8;
    1,  -12,    16;
    6,  -32,    32;
   -1,   24,   -80,    64;
   -8,   80,  -192,   128;
    1,  -40,   240,  -448,   256;
   10, -160,   672, -1024,   512;
   -1,   60,  -560,  1792, -2304, 1024;
  -12,  280, -1792,  4608, -5120, 2048;
  ...
With zeros, triangle begins:
   1;
   0,   2;
  -1,   0,   4;
   0,  -4,   0,    8;
   1,   0, -12,    0,   16;
   0,   6,   0,  -32,    0,    32;
  -1,   0,  24,    0,  -80,     0,   64;
   0,  -8,   0,   80,    0,  -192,    0,   128;
   1,   0, -40,    0,  240,     0, -448,     0,   256;
   0,  10,   0, -160,    0,   672,    0, -1024,     0,   512;
  -1,   0,  60,    0, -560,     0, 1792,     0, -2304,     0, 1024;
   0, -12,   0,  280,    0, -1792,    0,  4608,     0, -5120,    0, 2048;
  ...
(End)
		

References

  • M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 796.

Crossrefs

Reflected version with zeros: A053118. Cf. A008310, A053112, A053117.

Programs

  • Mathematica
    a[n_, k_] := Coefficient[ ChebyshevU[n, x], x, k]; row[n_] := Table[a[n, k], {k, Mod[n, 2], n, 2}]; Table[row[n], {n, 0, 11}] // Flatten (* Jean-François Alcover, Oct 03 2012 *)