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!)
A333018 Number of free heptagonal polyforms with n cells on the heptagonal tiling of the hyperbolic plane. 1
1, 1, 1, 3, 10, 44, 249, 1513, 9992, 68305, 480748, 3450793, 25186583 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

The heptagonal tiling is represented by Schläfli symbol {7,3}.

This sequence is to A259352 what A000228 is to A108070.

This sequence is computed from via program by Christian Sievers in the Code Golf Stack Exchange link.

LINKS

Table of n, a(n) for n=0..12.

Code Golf Stack Exchange, Impress Donald Knuth by counting polyominoes on the hyperbolic plane

Wikipedia, Heptagonal tiling

Wikipedia, Polyform

PROG

Several programs are available via the Code Golf link.

CROSSREFS

Analogs with different Schläfli symbols are A000105 ({4,4}), A000207 ({3,oo}), A000228 ({6,3}), A000577 ({3,6}), A005036 ({4,oo}), A119611 ({4,5}), A330659 ({3,7}), and A332930 ({4,6}).

Cf. A108070, A259352.

Sequence in context: A240172 A167995 A000608 * A259352 A205803 A329258

Adjacent sequences:  A333015 A333016 A333017 * A333019 A333020 A333021

KEYWORD

nonn,more,hard

AUTHOR

Peter Kagey, Mar 05 2020

EXTENSIONS

a(9)-a(12) from Ed Wynn, Feb 14 2021

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 June 12 23:15 EDT 2021. Contains 344979 sequences. (Running on oeis4.)