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).

7, 173, 11731, 2117317, 421173173, 34211731733, 1342117317337, 813421173173377, 28134211731733771, 4281342117317337713, 142813421173173377131, 21428134211731733771317, 2214281342117317337713171, 2022142813421173173377131711, 1120221428134211731733771317111

Offset: 1

Author

Amarnath Murthy, Sep 28 2002

Keywords

• base
• nonn

Crossrefs

Cf. A075595, A075596, A075597, A075598, A075600, A075601, A075602.

Extensions

More terms from Sascha Kurz, Jan 20 2003

Further terms from Ray G. Opao, Nov 26 2004

a(14)-a(15) corrected by Sean A. Irvine, Feb 26 2025