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A068724 Number of solenoidal flows (flow in = flow out) in a 5 X 5 square array with integer velocities -n .. n. 3
1, 569397, 1305759171, 251611610655, 13336307324915, 322309309862183 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..5.

EXAMPLE

Sample flows (. represents a space):

Numbers in long rows are on cell walls showing velocity rightward.

Numbers in long columns are on cell floors showing velocity downwards.

5 X 5 cell centers are at the intersection of long rows and long columns.

n=1:

.. 0 . 0 . 0 . 0 . 0

.0. -1. -1. -1. -1 . 0

.. 1 . 0 . 0 . 0. -1

.0 . 0. -1. -1 . 0 . 0

.. 1 . 1 . 0. -1. -1

.0 . 0 . 0 . 0 . 0 . 0

.. 1 . 1 . 0. -1. -1

.0 . 0 . 1 . 1 . 0 . 0

.. 1 . 0 . 0 . 0. -1

.0 . 1 . 1 . 1 . 1 . 0

.. 0 . 0 . 0 . 0 . 0

n=2:

.. 0 . 0 . 0 . 0 . 0

.0. -2. -1. -1. -1 . 0

.. 2. -1 . 0 . 0. -1

.0 . 0. -2. -2. -1 . 0

.. 2 . 1 . 0. -1. -2

.0 . 0. -1. -1 . 0 . 0

.. 2 . 2 . 0. -2. -2

.0 . 0 . 2 . 2 . 0 . 0

.. 2 . 0 . 0 . 0. -2

.0 . 2 . 2 . 2 . 2 . 0

.. 0 . 0 . 0 . 0 . 0

CROSSREFS

Cf. 2 X 2=1, 3, 5, 7..., 3 X 3 A068722, 4 X 4 A068723, 6x6 A068725, by velocity limit 1..13 A068726-A068738.

Sequence in context: A237935 A237693 A156412 * A233651 A288085 A121169

Adjacent sequences:  A068721 A068722 A068723 * A068725 A068726 A068727

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 26 2002

STATUS

approved

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Last modified April 1 10:33 EDT 2020. Contains 333159 sequences. (Running on oeis4.)