A318778 Number of different positions that an elementary sphinx can occupy in a sphinx of order n.

1, 28, 128, 300, 544, 860, 1248, 1708, 2240, 2844

Offset

1,2

Links

Table of n, a(n) for n=1..10.

Craig Knecht, 33 positions that a flacon occupies in a S4 sphinx - animated.

Craig Knecht, Bottom row surface tension.

Craig Knecht, Order Two Sphinx - 28 positions.

Craig Knecht, Order three sphinx - 128 positions.

Craig Knecht, Various shapes positioned in a order 4 sphinx.

Formula

Conjectures from Colin Barker, Nov 13 2018: (Start)

G.f.: x*(1 + 25*x + 47*x^2 - x^3) / (1 - x)^3.

a(n) = 44 - 80*n + 36*n^2 for n>1.

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

(End)

Crossrefs

Cf. A279887, A317541, A318897.

Sequence in context: A327750 A044360 A044741 * A184679 A123376 A192796

Adjacent sequences: A318775 A318776 A318777 * A318779 A318780 A318781

Keyword

nonn,more

Author

Craig Knecht, Sep 10 2018

Status

approved