%I #6 Jul 20 2021 23:45:26
%S 9,11,45,18281,32769,56891,180689,330539,959481,1850201,3247409,
%T 4940219,2425563239,2575561739,6003563495,7245212645,7770160145,
%U 4983798265289,5049762270381,5534298528989,5603798594169
%N Numbers k such that k concatenated with k-1 gives the product of two numbers which differ by 7.
%Y Cf. A116205, A115429, A116153, A116160, A116283.
%K nonn,base
%O 1,1
%A _Giovanni Resta_, Feb 06 2006