[seqfan] Re: Erased copies

Hans Havermann gladhobo at bell.net
Thu Oct 25 00:15:40 CEST 2018

EA: "A sequence I would like to see is the one dealing with the function F = (n+1)*a(n) that would generate, for the smallest a(1), more than 100 terms." ... "A friend of mine thinks that no integer < 10000000 generates any 100-term sequence, according to a program he wrote: the longest sequence would have 78 terms and the smallest generating-term would be 19128."

A small personal issue with the 19128 solution. If you allow a(1) = 19128 (=> 38256 => 4768 etc.), then you are essentially treating that first (generating) term differently from all the others in the sequence by not reducing it first. That can be fixed by noticing that a(1) = 69528 (=> 139056 => 4768 etc.) has the same sequence length.

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