A383083 The number of distinct straightedge-and-compass constructions that can be made with no lines and n circles.

1, 2, 1, 4, 44, 1084, 91192

Offset: 0

Author

Peter Kagey, Apr 16 2025

Keywords

• nonn
• more
• hard

Comments

A straightedge-and-compass construction starts with 2 points marked on the plane, traditionally (0,0) and (1,0). In the constructions counted by this sequence, only the compass is used. Circles can be drawn at any marked point through any other marked point, and new points are marked where circles intersect.

Links

• Wikipedia, Mohr-Mascheroni theorem
• Peter Kagey, Illustration of a(0)=1, a(1)=2, a(2)=1, and a(3)=4.
• Peter Kagey, Illustration of a(4)=44.

Crossrefs

Cf. A250001, A333944, A339266, A383082.