%I #9 Jul 18 2021 21:40:57

%S 1,13,41,653,2287,2723,5491,23240971,26823191,60249661,1841968537,

%T 2009317771,3044234903,3258336353,8166731261,9481619237,

%U 1281071245505271100098621541,1551605670846640136726379653

%N Numbers k such that k concatenated with k+7 gives the product of two numbers which differ by 7.

%Y Cf. A116153, A116147, A116208, A116210, A116215, A116340.

%K nonn,base

%O 1,2

%A _Giovanni Resta_, Feb 06 2006