Map folding ( $5 \times 5)$

The number of distinct ways to fold a $5 \times 5$ rectangle into a unit square.

Value: $186086600$ (186,086,600)

Updates

Lower bound: $186086600$ (186,086,600)
Reference unknown
[via Number of ways of folding an n X n sheet of stamps. - OEIS]
Upper bound: $186086600$ (186,086,600)
Reference unknown
[via Number of ways of folding an n X n sheet of stamps. - OEIS]