login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A236754 Number of irregular spirals (non-expanded loop) appearing with n center points. 1
1, 0, 6, 8, 120, 0, 5040, 4608, 362880, 0, 39916800 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

See A236535 for construction rule.

Conjecture: (1) For odd n all forms are non-expanded loops and equal to n!. (2) For n mod 4 = 0, there are both non-expanded 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: A013240 A161801 A211041 * A069660 A119001 A324987

Adjacent sequences:  A236751 A236752 A236753 * A236755 A236756 A236757

KEYWORD

nonn,more

AUTHOR

Kival Ngaokrajang, Jan 30 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 7 06:02 EDT 2020. Contains 336274 sequences. (Running on oeis4.)