A110788 Copies of 7 and 1 alternately such that every partial concatenation is a prime.

7, 1, 77, 1111, 77777, 1111111111, 77777777777777777777777, 111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111

Offset: 1

Author

Amarnath Murthy, Aug 13 2005

Keywords

• base
• nonn

Examples

			7, 71, 7177, 71771111, ... are all prime.
		

Crossrefs

Cf. A110774, A110775, A110776, A110777, A110778, A110780, A110781, A110782, A110783, A110789.

Extensions

More terms from Joshua Zucker, Jan 11 2006