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A141838 a(n) = first term that can be reduced in n steps via repeated interpretation of a(n) as a base b+1 number where b is the largest digit of a(n), such that b is always 4 so that each interpretation is base 5. Terms already fully reduced (i.e., single digits) are excluded. 6
14, 24, 44, 134, 1014, 13024, 404044, 100412134, 201201142014 (list; graph; refs; listen; history; text; internal format)



It is possible to compute additional terms by taking the last term, treating it as base-10 and converting to base-5. This will necessarily create a term which can converted back to base 10 yielding the previous term in the sequence which will itself yield N further terms. But there is no guarantee (except in base 2) that the term so derived will be the first term to produce a sequence of N+1 terms. There could be another, smaller, term which satisfies that requirement but which uses different terms. Pushing the last term of this sequence yields 201201142014 as a possible next term.


Table of n, a(n) for n=1..9.


a(3) = 44 because 44 is the first number that can produce a sequence of three terms by repeated interpretation as a base 5 number: [44] (base-5) --> [24] (base-5) --> [14] (base-5) --> [9]. Since 9 cannot be interpreted as a base 5 number, the sequence terminates with 14. a(1) = 14 because 14 is the first number that can be reduced once, yielding no further terms interpretable as base 5.


Cf. A091049, A141836, A141837, A141839, A141840, A141841, A141842.

Sequence in context: A164399 A164404 A211323 * A140499 A068365 A154038

Adjacent sequences:  A141835 A141836 A141837 * A141839 A141840 A141841




Chuck Seggelin (seqfan(AT)plastereddragon.com), Jul 10 2008


a(9) from Giovanni Resta, Feb 23 2013



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Last modified October 28 01:29 EDT 2021. Contains 348305 sequences. (Running on oeis4.)