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%I #6 Sep 26 2019 21:11:29
%S 979,89,189,289,389,489,589,689,789,889,989,99,199,299,399,499,599,
%T 699,799,899,999,10,110,210,310,410,510,610,710,810,910,1010,1110,
%U 1210,1310,1410,1510,1610,1710,1810,1910,2010,2110,2210,2310,2410,2510,2610,2710,2810,2910,3010,3110,3210
%N "Rotation" of n: swap the first [d/2] and last [d/2] digits, when n has d digits.
%C When n has an odd number of digits, the middle one remains at its place.
%C This operation, denoted "rotation" k -> rot(k) in sequences A086002, A086003, A086004, is indistinguishable from A004086 (reverse n) for numbers < 1000. Therefore the offset is chosen as to have 2/3 of the displayed terms beyond this limit and 1/3 below. This makes it easy to find the sequence searching for the terms near that limit, ..., 999, 10, 110, 210,....
%F a(n) = A004086(n) ("reverse n") for n < 1000.
%e a(123) = concat(3, 2, 1) = 321.
%e a(1234) = concat(34, 12) = 3412.
%e a(12345) = concat(45, 3, 12) = 45312.
%o (PARI) a(n)={n=digits(n); fromdigits(concat([n[#n\/2+1..#n],n[#n\2+1..#n\/2],n[1..#n\2]]))}
%Y Cf. A086002, A086003, A086004, A004086.
%K nonn,base
%O 979,1
%A _M. F. Hasler_, Sep 26 2019
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