The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A337867 Number of polyfetts (or polifetti) with n cells, identifying mirror images. 2
 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 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 * A116348 A043088 A175710 Adjacent sequences:  A337864 A337865 A337866 * A337868 A337869 A337870 KEYWORD nonn,hard,more AUTHOR George Sicherman, Sep 27 2020 STATUS approved

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

Last modified May 18 22:37 EDT 2022. Contains 353826 sequences. (Running on oeis4.)