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.

A327809 Regular triangle, coefficients of the polynomial P(n)(x) = (-1)^(n+1)*(2*n+1)*binomial(2*n, n)*Sum_{i=0..n} x^i*binomial(n, i)/(n+i+1).

Original entry on oeis.org

-1, 3, 2, -10, -15, -6, 35, 84, 70, 20, -126, -420, -540, -315, -70, 462, 1980, 3465, 3080, 1386, 252, -1716, -9009, -20020, -24024, -16380, -6006, -924, 6435, 40040, 108108, 163800, 150150, 83160, 25740, 3432, -24310, -175032, -556920, -1021020, -1178100, -875160, -408408, -109395, -12870
Offset: 0

Views

Author

Michel Marcus, Sep 26 2019

Keywords

Examples

			Triangle begins:
     -1;
      3,     2;
    -10,   -15,     -6;
     35,    84,     70,     20;
   -126,  -420,   -540,   -315,   -70;
    462,  1980,   3465,   3080,   1386,   252;
  -1716, -9009, -20020, -24024, -16380, -6006, -924;
  ...
		

Crossrefs

Cf. A046899 (Q(x) polynomials, up to sign).
Cf. A001700 (1st column, up to sign), A033876 (right diagonal, up to sign).

Programs

  • PARI
    pol(n) = (-1)^(n+1)*(2*n+1)*binomial(2*n, n)*sum(i=0, n, x^i*binomial(n, i)/(n+i+1));
    row(n) = Vecrev(pol(n));
    tabl(nn) = for (n=0, nn, print(row(n)));