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.

A287041 Column 1 of A286783.

Original entry on oeis.org

5, 77, 1044, 14784, 227877, 3862305, 71983440, 1469813400, 32718512925, 789901955325, 20578796752500, 575836554270600, 17232413940017325, 549370878062313825, 18591830334684129600, 665771181527890746000, 25154357611638416671125, 1000094581801108086418125, 41741166856778766269392500
Offset: 2

Views

Author

Gheorghe Coserea, May 19 2017

Keywords

Crossrefs

Cf. A286783.

Programs

  • PARI
    A286781_ser(N, t='t) = {
      my(x='x+O('x^N), y0=1+O('x^N), y1=0, n=1);
      while(n++,
        y1 = (1 + x*y0 + 2*x^2*y0')*(1 - x*y0*(1-t))/(1-x*y0)^2;
        if (y1 == y0, break()); y0 = y1;);
      y0;
    };
    Kol(K, N=20) = {
      my(s = A286781_ser(N+K+1, 't+O('t^(K+1))),
         p = (1 + x*s + 2*x^2*s')/(1-x*s)^2);
      vector(N, n, polcoeff(polcoeff(p, K+n), K));
    };
    Kol(1)