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%I #6 Mar 21 2015 04:49:16
%S 1,4,5,115,148,247,346,371,445,528,7606,8376,9157,12478,16528,19834,
%T 22477,25103,28546,31989,32476,33057,38875,40495,42475,45761,46335,
%U 50494,52474,52647,59533,61483,62473,66445,72472,83461,94450,1165288
%N Concatenating n with n+1 (in base 10) gives a number which is the product of 2 palindromes.
%C Members that have an even number of digits are rare: 7606, 8376, 9157, ..., . - _Robert G. Wilson v_
%e 3305733058 = 45454*72727.
%t palQ[n_] := Block[{id = IntegerDigits[n]}, id == Reverse[id]]; t = {}; Do[p = 10^Floor[Log[10, n] + 1]n + n + 1; If[ MemberQ[ Union[Times @@@ Tuples[ Select[ Most@ Rest@ Divisors@p, palQ[ # ] &], 2]], p], AppendTo[t, n]], {n, 1504947}]; t (* _Robert G. Wilson v_, Jan 31 2006 *)
%K base,nonn
%O 1,2
%A _Giovanni Resta_, Jan 31 2006