

A236755


Number of irregular spiral (expanded spiral) appearing with n center points.


1



0, 2, 0, 16, 0, 720, 0, 35712, 0, 3628800, 0
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OFFSET

1,2


COMMENTS

See A236535 for construction rule.
Conjecture: (1) For even n; except n mod 4 = 0; all forms are expanded spirals and equal to n!. (2) For n mod 4 = 0, there are both nonexpanded loops and expanded spirals.


LINKS

Table of n, a(n) for n=1..11.
Kival Ngaokrajang, Illustration of irregular spirals, center points = 1..6
Kival Ngaokrajang, Small Basic program


CROSSREFS

Cf. A014105 (2 center points); A234902, A234903, A234904, A236535 (3 center points); A235088, A235089 (4 center points); A236326, A236327 (5 center points).
Sequence in context: A025600 A009006 A155585 * A057375 A009045 A060313
Adjacent sequences: A236752 A236753 A236754 * A236756 A236757 A236758


KEYWORD

nonn,more


AUTHOR

Kival Ngaokrajang, Jan 30 2014


STATUS

approved



