Number of functions constructed from n instances of variable x using operators + (add), * (multiply), and parentheses.

A307900

Number of functions constructed from n instances of variable x using operators + (add), * (multiply), and parentheses.

Terms

    a(0) =1a(1) =2a(2) =4a(3) =10a(4) =24a(5) =61a(6) =150a(7) =382a(8) =964a(9) =2452a(10) =6307a(11) =16379a(12) =42989a(13) =113965a(14) =305035a(15) =823632a(16) =2241814a(17) =6145670a(18) =16956972a(19) =47059076a(20) =131279567

External references