cp's OEIS Frontend

A228728 a(1)=1, a(2)=2 and for n > 2, a(n) is the least integer > a(n-1) such that there is a permutation b(1), ..., b(n) of a(1), ..., a(n) with b(1) = a(1) and b(n) = a(n), and with the n numbers |b(1)-b(2)|, |b(2)-b(3)|, ..., |b(n-1)-b(n)|, |b(n)-b(1)| pairwise distinct.