The On-Line Encyclopedia of Integer Sequences (OEIS)

A337867 revision #23

A337867

Number of polyfetts (or polifetti) with n cells, identifying mirror images.

1, 10, 90, 1414, 23136, 406093, 7303813, 134027098

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

A polyfett is a generalized polyabolo (or polytan). Its cells are equal isosceles right triangles on the quadrille grid, which may be joined along equal edges or at vertices.

Polyfetts are to polyaboloes what polyplets (or polykings) are to polyominoes.

LINKS

Table of n, a(n) for n=1..8.

Sean A. Irvine, Java program (github)

George Sicherman, Catalogue of Polyfetts

George Sicherman, polyaboloes.c

EXAMPLE

For n = 2, a(2) = 10. Two polyabolo cells can be joined at edges to form 3 different diaboloes, or at corners to form 7 different proper difetts.

PROG

See link to Unix C program polyaboloes.c under LINKS.

CROSSREFS

Cf. A006074.

Sequence in context: A322647 A243106 A046706 * A374228 A116348 A043088

Adjacent sequences: A337864 A337865 A337866 * A337868 A337869 A337870

KEYWORD

nonn,hard,more

AUTHOR

George Sicherman, Sep 27 2020

STATUS

approved