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A330659 The number of free polyiamonds with n cells on an order-7 triangular tiling of the hyperbolic plane. 3
1, 1, 1, 1, 3, 4, 12, 27, 78, 208, 637, 1870, 5797, 17866, 56237, 177573, 566904, 1818527, 5874180, 19065038 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

This gives the number of polyforms with n cells in the hyperbolic tiling with Schläfli symbol {3,7}.

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..19.

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

Wikipedia, Order-7 triangular tiling

Wikipedia, Polyiamond

PROG

Several working programs are available via the Code Golf link.

CROSSREFS

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

Sequence in context: A000942 A255436 A197459 * A000207 A002986 A147569

Adjacent sequences:  A330656 A330657 A330658 * A330660 A330661 A330662

KEYWORD

nonn,more

AUTHOR

Peter Kagey, Mar 01 2020

EXTENSIONS

a(11)-a(19) from Ed Wynn, Feb 14 2021

STATUS

approved

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Last modified September 23 12:43 EDT 2021. Contains 347617 sequences. (Running on oeis4.)