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A130623
Number of polyhexes with perimeter at most 2n.
0
0, 0, 1, 1, 2, 3, 6, 8, 20, 34, 84, 182
OFFSET
1,5
COMMENTS
The perimeter of a polyhex is always even.
Partial sums of A057779.
a(2n+1) >= A131467(n).
CROSSREFS
Cf. A038142 (planar cata-polyhexes with n cells).
Cf. A057779 (hexagonal polyominoes with perimeter 2n).
Cf. A131467 (planar polyhexes with at most n cells).
Sequence in context: A064450 A217137 A248824 * A072847 A274371 A339589
KEYWORD
hard,more,nonn
AUTHOR
Tanya Khovanova, Aug 11 2007
EXTENSIONS
Offset corrected by John Mason, Jan 16 2023
STATUS
approved