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A075421
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Trajectory of n under the Reverse and Add! operation carried out in base 4 (presumably) does not reach a palindrome and (presumably) does not join the trajectory of any term m < n.
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14
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290, 318, 719, 795, 799, 1210, 3903, 4199, 4207, 4219, 4236, 4278, 4279, 4294, 4326, 4333, 4334, 4338, 4402, 4598, 4662, 4726, 5046, 5357, 6157, 6174, 7246, 7247, 7295, 7407, 7549, 8063, 8191, 9211, 12319, 12431, 12463, 12539, 15487, 16519, 16587
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| For 318 (cf. A075153), 266718 (cf. A075466) and 270798 (cf. A075467) one can prove that the base 4 trajectory does not contain a palindrome. A proof for 290 (cf. A075299) has not been found up to now. 4398859679359 is another known candidate (obtained from a remark of David Seal, cf. Links) for a term whose trajectory is provably palindrome-free, but is not secured that it does not join the trajectory of some term m < n. - If the trajectory of an integer k joins the trajectory of a smaller integer which is a term of the present sequence, then this occurs after very few Reverse and Add! steps (at most 28 for k < 20000). On the other hand, the trajectories of the terms listed above do not join the trajectory of any smaller term within at least 1000 steps.
Base 4 analogue of A063048 (base 10) and A075252 (base 2); subsequence of A075420.
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LINKS
| Klaus Brockhaus, Illustration: Distribution of terms below 2000000
D. Seal, Results
Index entries for sequences related to Reverse and Add!
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EXAMPLE
| 719 is a term since the trajectory of 719 (presumably) does not lead to an integer which occurs in the trajectory of 290 or of 318.
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CROSSREFS
| Cf. A063048, A075252, A075420, A075299, A075153, A075466, A075467, A091675.
Sequence in context: A129245 A186553 A075420 * A090839 A158255 A075299
Adjacent sequences: A075418 A075419 A075420 * A075422 A075423 A075424
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KEYWORD
| base,nonn
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AUTHOR
| Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Sep 18 2002, revised Jan 28 2004
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