A355562 Number of blunt polypons with n cells.

0, 1, 1, 2, 1, 5, 3, 10, 13, 31, 44, 103, 169, 360, 643, 1317, 2479, 5036, 9716, 19592, 38511, 77465, 153686, 309093, 617426, 1243392, 2496186, 5035612, 10145109

Offset

1,4

Comments

Polypons are defined in A057784. A blunt polypon is a polypon with no internal angle of 30 degrees.

Comments by Joseph Myers in A057784 regarding division of hexagons also apply to this sequence.

Links

Table of n, a(n) for n=1..29.

Andrew Clarke, Other Polyforms [beware of errors for this particular form]

Sean A. Irvine, Java program (github)

Sean A. Irvine, The 5 blunt 6-pons

Sean A. Irvine, The 44 blunt 11-pons

Nico Pelleriti, Rust program for exact computation through a(29) (github)

Crossrefs

Cf. A057784, A057785 (erroneous version).

Sequence in context: A179218 A131119 A114901 * A194809 A113178 A108362

Adjacent sequences: A355559 A355560 A355561 * A355563 A355564 A355565

Keyword

nonn,nice,hard,more,changed

Author

Sean A. Irvine, Jul 06 2022

Extensions

a(29) from Nico Pelleriti, Jun 22 2026

Status

approved