a(n) is the smallest positive integer that cannot be obtained using at most n-1 of the integers {1, 2, ..., n} using each number at most once and the operators +, -, *, /.

A071985

a(n) is the smallest positive integer that cannot be obtained using at most n-1 of the integers {1, 2, ..., n} using each number at most once and the operators +, -, *, /.

Terms

    a(0) =1a(1) =3a(2) =7a(3) =17a(4) =47a(5) =158a(6) =681a(7) =3209a(8) =17989a(9) =104289a(10) =635867

External references