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.

A271316 Triangle of numbers where T(n,k) is the number of k-dimensional faces on a partially truncated n-cube, 0 <= k <= n.

Original entry on oeis.org

1, 2, 1, 8, 8, 1, 24, 36, 14, 1, 64, 128, 88, 24, 1, 160, 400, 400, 200, 42, 1, 384, 1152, 1520, 1120, 444, 76, 1, 896, 3136, 5152, 5040, 2968, 980, 142, 1, 2048, 8192, 16128, 19712, 15456, 7616, 2160, 272, 1, 4608, 20736, 47616, 69888, 68544, 45024, 19104, 4752, 530, 1, 10240, 51200, 134400, 230400, 271488, 223104, 126240, 47040, 10420, 1044, 1
Offset: 0

Views

Author

Vincent J. Matsko, Apr 03 2016

Keywords

Examples

			Triangle begins:
1;
2, 1;
8, 8, 1;
24, 36, 14, 1;
64, 128, 88, 24, 1;
...
Row 2 describes an octagon: 8 vertices and 8 edges.
Row 3 describes a truncated cube: 24 vertices, 36 edges, and 14 faces.
		

Crossrefs

Cf. A038207 (n-cube).

Programs

  • Mathematica
    Flatten[Table[
      CoefficientList[
       D[1 + Exp[(x + 2) z] + ( Exp[2 z (x + 1)] - (x + 1) Exp[2 z])/x, {z,
          k}] /. z -> 0, x], {k, 0, 10}]]

Formula

G.f. for rows (n > 0): (x+2)^n + 2^n*(x+1)*((x+1)^(n-1)-1)/x.
O.g.f: 1 + 1/(1-(x+2)*y) + 1/(x*(1-2*y*(x+1))) - (x+1)/(x*(1-2*y)).
E.g.f: 1 + exp((x+2)*z) + (exp(2*z*(x+1))-(x+1)*exp(2*z))/x.