a(1) = 7 and then the smallest prime that is obtained by placing digits on both sides of the previous term. Or smallest prime that encompasses a(n-1).

A075599

a(1) = 7 and then the smallest prime that is obtained by placing digits on both sides of the previous term. Or smallest prime that encompasses a(n-1).

Terms

    a(0) =7a(1) =173a(2) =11731a(3) =2117317a(4) =421173173a(5) =34211731733

External references