%I #7 Nov 14 2021 12:39:39
%S 7,1,77,1111,77777,1111111111,77777777777777777777777,
%T 111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
%N Copies of 7 and 1 alternately such that every partial concatenation is a prime.
%e 7, 71, 7177, 71771111, ... are all prime.
%Y Cf. A110774, A110775, A110776, A110777, A110778, A110780, A110781, A110782, A110783, A110789.
%K base,nonn
%O 1,1
%A _Amarnath Murthy_, Aug 13 2005
%E More terms from _Joshua Zucker_, Jan 11 2006