A188785 Number of 2-step self-avoiding walks on an n X n X n X n 4-cube summed over all starting positions.

0, 64, 432, 1536, 4000, 8640, 16464, 28672, 46656, 72000, 106480, 152064, 210912, 285376, 378000, 491520, 628864, 793152, 987696, 1216000, 1481760, 1788864, 2141392, 2543616, 3000000, 3515200, 4094064, 4741632, 5463136, 6264000, 7149840

Offset

1,2

Comments

Row 2 of A188784.

Links

R. H. Hardin, Table of n, a(n) for n = 1..43

Formula

Empirical: a(n) = 8*n^4 - 8*n^3.

Conjectures from Colin Barker, Apr 28 2018: (Start)

G.f.: 16*x^2*(4 + 7*x + x^2) / (1 - x)^5.

a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.

(End)

Crossrefs

Cf. A188784.

Sequence in context: A304847 A316544 A306059 * A317237 A282771 A188821

Adjacent sequences: A188782 A188783 A188784 * A188786 A188787 A188788

Keyword

nonn

Author

R. H. Hardin, Apr 10 2011

Status

approved