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A337867
Number of polyfetts (or polifetti) with n cells, identifying mirror images.
2
1, 10, 90, 1414, 23136, 406093, 7303813, 134027098
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
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
(C) /* See link to Unix C program polyaboloes.c under LINKS. */
CROSSREFS
Cf. A006074.
Sequence in context: A322647 A243106 A046706 * A374228 A116348 A043088
KEYWORD
nonn,hard,more
AUTHOR
George Sicherman, Sep 27 2020
STATUS
approved