Map folding ($2 \times 18)$
The number of distinct ways to fold a $2 \times 18$ rectangle into a unit square.
Value: $5545305620064$ (5,545,305,620,064)
Updates
-
Lower bound: $5545305620064$
(5,545,305,620,064)
Reference unknown
[via Number of ways of folding a 2 X n strip of stamps. - OEIS] -
Upper bound: $5545305620064$
(5,545,305,620,064)
Reference unknown
[via Number of ways of folding a 2 X n strip of stamps. - OEIS]