A305606 Number of blunt polytans (polyaboloes) with n cells, identifying mirror images. A blunt polytan is one with no acute corners.

0, 1, 0, 2, 2, 5, 6, 23, 45, 138, 347, 1007, 2751, 7998, 22638, 65708, 189505, 551798, 1606383, 4697905

Offset

1,4

Links

Table of n, a(n) for n=1..20.

George Sicherman, Catalogue of Blunt Polytans

Example

There are 3 ditans.  Only the square ditan lacks acute corners, so a(2)=1.

Crossrefs

Cf. A006074, number of polyaboloes with n cells, identifying mirror images.

Sequence in context: A329908 A295198 A080880 * A369634 A120843 A205674

Adjacent sequences: A305603 A305604 A305605 * A305607 A305608 A305609

Keyword

nonn,hard,more

Author

George Sicherman, Jun 05 2018

Extensions

a(15)-a(20) from John Mason, Jan 07 2022

Status

approved