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A007499
Number of cases considered in a particular algorithm for enumerating hexaflexagrams.
(Formerly M0598)
1
2, 3, 4, 12, 20, 55, 127, 371, 1037, 3249, 10071, 32913, 108112, 363618, 1233938, 4244102, 14716095, 51480027, 181312939
OFFSET
1,1
COMMENTS
See O'Reilly reference for precise definition.
REFERENCES
Thomas J. O'Reilly, Classifying and Counting Hexaflexagrams, J. Rec. Math., 8 (1976), 182-187.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Sean A. Irvine, Java program (github)
Thomas J. O'Reilly, Classifying and Counting Hexaflexagrams, J. Rec. Math., 8 (1976), 182-187. [Annotated scanned copy]
CROSSREFS
Cf. A000207.
Sequence in context: A331945 A275067 A295620 * A117555 A243392 A239943
KEYWORD
nonn,more
AUTHOR
EXTENSIONS
Title clarified and a(11)-a(19) from Sean A. Irvine, Jul 12 2022
STATUS
approved