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Numbers k such that k concatenated with k-7 gives the product of two numbers which differ by 9.
5

%I #6 Jul 21 2021 22:47:12

%S 13,493,607,629,757,17927,33247,93869,19467217,31223879,72757727,

%T 13454739732766891651472740499,40093333713615672956030023507,

%U 48089152118689474641229584727,66424317743191484432891678269

%N Numbers k such that k concatenated with k-7 gives the product of two numbers which differ by 9.

%Y Cf. A116109, A116113, A116180, A116245.

%K nonn,base

%O 1,1

%A _Giovanni Resta_, Feb 06 2006