Number of distinct values taken by 5^5^...^5 (with n 5's and parentheses inserted in all possible ways).

A145545

Number of distinct values taken by 5^5^...^5 (with n 5's and parentheses inserted in all possible ways).

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =9a(5) =20a(6) =48a(7) =115a(8) =285a(9) =715a(10) =1826a(11) =4711a(12) =12303a(13) =32387a(14) =85964a(15) =229662a(16) =617300a(17) =1667787a(18) =4527290a(19) =12340688a(20) =33766612a(21) =92707834a(22) =255329106

External references