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%I #8 May 13 2017 10:20:49
%S 1,23,345,4567,56789,67891011,78910111213,89101112131415,
%T 91011121314151617,10111213141516171819,1112131415161718192021,
%U 121314151617181920212223
%N Concatenation of n numbers starting with n.
%H Michael De Vlieger, <a href="/A077309/b077309.txt">Table of n, a(n) for n = 1..333</a>
%t Table[FromDigits@ Flatten@ Take[#, {n, n + (n - 1)}], {n, Ceiling[Length[#]/2]}] &@ Array[IntegerDigits, 23] (* _Michael De Vlieger_, May 13 2017 *)
%K base,easy,nonn
%O 1,2
%A _Amarnath Murthy_, Nov 03 2002
%E a(7) corrected by _Michael De Vlieger_, May 13 2017