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%I #9 Jul 03 2020 12:14:22
%S 2,33,444,5555,66666,777777,8888888,99999999,1111111110,23333333231,
%T 2345555545332,244567776755433,25466789897765534,2647689001998775635,
%U 274869910212099785736,28497092031222200795837,2950719304132232301805938
%N Sum of the forward and reverse concatenations of 1 to n.
%H Harvey P. Dale, <a href="/A078262/b078262.txt">Table of n, a(n) for n = 1..369</a>
%e a(3) = 123 +321 = 444,a(10) = 12345678910 + 10987654321 = 23333333231.
%t Table[With[{c1=FromDigits[Flatten[IntegerDigits/@Range[n]]],c2= FromDigits[ Flatten[ IntegerDigits/@Range[n,1,-1]]]},c1+c2],{n,20}] (* _Harvey P. Dale_, Jul 03 2020 *)
%Y Cf. A078263.
%K base,nonn
%O 1,1
%A _Amarnath Murthy_, Nov 24 2002
%E More terms from _Sascha Kurz_, Jan 04 2003
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