%I
%S 123,2345,3456,4567,5678,6789,7890,8901,9012,10123,11234,12345,13456,
%T 14567,15678,16789,17890,18901,19012,20123,21234,22345,23456
%N Append three digits, each increasing by one modulo 10 from the last digit the of the positive integers. 0 > 123, 1 > 1234 2 > 2345, ... , 9 > 9012, 10 >10123, etc.
%F a(n) = 1000n + O(1)
%K easy,nonn,base
%O 0,1
%A Felix Tubiana (fat2(AT)columbia.edu), Oct 30 2009
