A071905 a(n) is the smallest positive integer (which is a polynomial of degree 0) that cannot be obtained using the polynomials {x, x+1, ..., x+n} using each polynomial at most once and the operations +, -, *, /.
1, 2, 3, 5, 7, 13, 29, 67, 103, 373
Offset: 0
Examples
a(3)=5 because using {x, x+1, x+2, x+3} we can get x+1-x=1, x+2-x=2, x+3-x=3, (x+2-x)*(x+3-(x+1))=4 but we cannot obtain 5 in the same way.