A156120 - OEIS

%I #6 Jul 22 2014 22:08:57

%S 2423,102101,114113,210209,264263,270269,330329,342341,414413,762761,

%T 774773,840839,852851,912911,10021001,11101109,17641763,20222021,

%U 21302129,22322231,26822681,27242723,28322831,32523251,36723671

%N First of a prime pair formed by concatenating n with n-1, and a matching prime (not shown) formed by concatenating n-2 with n-3.

%e Example: 2423 and matching prime 2221 (not shown), where n = 24.

%K nonn,base

%O 1,1

%A _Ki Punches_, Feb 16 2009

%E Edited and extended by _Ray Chandler_, Feb 20 2009