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.

A188151 Number of 6-step self-avoiding walks on an n X n square summed over all starting positions.

Original entry on oeis.org

0, 0, 128, 800, 2112, 4008, 6472, 9504, 13104, 17272, 22008, 27312, 33184, 39624, 46632, 54208, 62352, 71064, 80344, 90192, 100608, 111592, 123144, 135264, 147952, 161208, 175032, 189424, 204384, 219912, 236008, 252672, 269904, 287704, 306072
Offset: 1

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Author

R. H. Hardin, Mar 22 2011

Keywords

Comments

Row 6 of A188147.

Examples

			Some solutions for 3 X 3:
  5 4 3   0 6 7   2 3 4   6 7 0   0 7 0   7 4 3   1 0 0
  6 0 2   4 5 0   1 0 5   5 2 1   1 6 5   6 5 2   2 7 6
  7 0 1   3 2 1   0 7 6   4 3 0   2 3 4   0 0 1   3 4 5
		

Crossrefs

Cf. A188147.

Formula

Empirical: a(n) = 284*n^2 - 1228*n + 1152 for n>4.
Conjectures from Colin Barker, Apr 27 2018: (Start)
G.f.: 8*x^3*(16 + 52*x + 12*x^2 - 7*x^3 - 2*x^4) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>7.
(End)