a(n) is the smallest prime p such that there is a multiplicative subgroup H of Z/pZ, of odd size and of index 2n, such that for any two cosets H1 and H2 of H, H1 + H2 contains all of (Z/pZ)\0.

A282001

a(n) is the smallest prime p such that there is a multiplicative subgroup H of Z/pZ, of odd size and of index 2n, such that for any two cosets H1 and H2 of H, H1 + H2 contains all of (Z/pZ)\0.