A392391 Number of fixed polybends with n cells.

4, 8, 16, 29, 52, 96, 176, 310, 556, 1000, 1800, 3159, 5612, 9992, 17788, 31160, 55076, 97452, 172424, 301752, 531460, 936684, 1650924, 2886702, 5071604, 8914664, 15670616, 27380368, 48016600, 84237912, 147791616, 258063306, 451933712, 791685544, 1386941316, 2420447444, 4234178976

Offset

1,1

Comments

See A392389 for details.

Links

Table of n, a(n) for n=1..37.

Formula

a(n) = 4*A392390(n) if n is odd, because a polybend with an odd number of cells cannot have any rotational symmetry.

Crossrefs

Cf. A390995, A392389 (free), A392390 (one-sided).

Sequence in context: A302508 A386597 A030119 * A034451 A099992 A301149

Adjacent sequences: A392388 A392389 A392390 * A392392 A392393 A392394

Keyword

nonn

Author

Pontus von Brömssen, Jan 10 2026

Status

approved