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%I #21 Feb 28 2020 00:04:42
%S 1,2,3,4,5,6,7,8,9,10,11,12,13,32,33,34,35,36,37,74,75,76,77,78,79,98,
%T 99,100,101,102,103,302,303,304,305,306,307,704,705,706,707,708,709,
%U 908,909,910,911,120,121,122,123,124,125,126,127,722,723,724,725,726,727,728,729,730,731,732,733,338,339,340,341,342,343
%N A variant of the Syracuse-like routine visible in A323175, avoiding duplicates (and loops). See the Comments section.
%C Here is the original 4-step routine:
%C (1) Start with any integer > 0
%C (2) Add 1 and print
%C (3) If the result is a composite number go to (2), otherwise go to (4)
%C (4) Reverse the digits of the result and go to (2)
%C In this variant, if the above routine produces a duplicate, we replace this duplicate with the smallest integer not yet present in the sequence, print it and go to the instruction (2).
%C This sequence is a permutation of the positive integers.
%H Jean-Marc Falcoz, <a href="/A323204/b323204.txt">Table of n, a(n) for n = 1..10001</a>
%e This sequence differs from A323175 by construction as A323175 is finite, ending with a(143) = 809; this sequence shares the same 143 first terms, then a(144) = 14 (as 14 is the smallest integer not yet present in the sequence), etc.
%Y Cf. A323175 (the original Syracuse-like routine explained).
%K base,nonn
%O 1,2
%A _Eric Angelini_ and _Jean-Marc Falcoz_, Jan 07 2019