Number of distinct values taken by 2^2^...^2 (with n 2's and parentheses inserted in all possible ways).

A002845

Number of distinct values taken by 2^2^...^2 (with n 2's and parentheses inserted in all possible ways).

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =8a(6) =17a(7) =36a(8) =78a(9) =171a(10) =379a(11) =851a(12) =1928a(13) =4396a(14) =10087a(15) =23273a(16) =53948a(17) =125608a(18) =293543a(19) =688366a(20) =1619087a(21) =3818818a(22) =9029719a(23) =21400706a(24) =50828664a(25) =120963298a(26) =288405081a(27) =688821573a(28) =1647853491a(29) =3948189131

External references