%I A075024
%S A075024 1,11,37,101,271,37,4649,137,333667,12345678910987654321,
%T A075024 17636684157301569664903,2799473675762179389994681,
%U A075024 2354041513534224607850261,2068140300159522133,498056174529497
%N A075024 a(1) = 1, a(n) = the largest prime divisor of the number C(n) = concatenation 
               of 1,2,3... up to n then reverse up to 1.
%e A075024 a(5) = 271 as 123454321= 41*41*271*271.
%Y A075024 Cf. A075019, A075020, A075021, A075022, A075023.
%Y A075024 Sequence in context: A124479 A140373 A003020 this_sequence A152094 A147556 
               A120833
%Y A075024 Adjacent sequences: A075021 A075022 A075023 this_sequence A075025 A075026 
               A075027
%K A075024 base,nonn
%O A075024 1,2
%A A075024 Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Sep 01 2002
%E A075024 More terms from Sascha Kurz (sascha.kurz(AT)uni-bayreuth.de), Jan 03 
               2003