"Nothing deep here" I said, referring to the class of "lexicographically earliest sequences". I take it back. A282317, the lex. earliest cube-free binary sequence, needed an argument from topology to show that it exists. So A309151 may not be so trivial. The present definition of A309151 is "Lexicographically earliest sequence of distinct terms starting with a(1) = 1 such that a(n) doesn't share any digit with the cumulative sum a(1) + a(2) + a(3) + ... + a(n-1) + a(n)" But this is the finite sequence 1,2,3,4, no? It can't be extended! It satisfies the conditions, and any other sequence satisfying the conditions must start 1,2,3,m with m >= 5. Maybe the authors should modify the definition to say "Lexicographically earliest infinite sequence of distinct terms starting with a(1) = 1 such that a(n) doesn't share any digit with the cumulative sum a(1) + a(2) + a(3) + ... + a(n-1) + a(n)."? But then we don't know how many of the present terms are correct! I'm sending the sequence back to the editing stack. On Sun, Jul 14, 2019 at 10:14 PM Neil Sloane <njasloane@gmail.com> wrote:
Hans, They claim that 1000 terms of the 1079-term b-file are correct, and imply that the remaining 79 terms are too. So I approved it, hoping that someone like you would check it when they saw that comment.
Furthermore, this is a member of the class of "lexicographically earliest sequences" , of which we have a large number in the OEIS, and there is no mystery about them. Backtracking is all it takes. Nothing deep here.
Best regards Neil
Neil J. A. Sloane, President, OEIS Foundation. 11 South Adelaide Avenue, Highland Park, NJ 08904, USA. Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ. Phone: 732 828 6098; home page: http://NeilSloane.com Email: njasloane@gmail.com
On Sun, Jul 14, 2019 at 9:58 PM Hans Havermann <gladhobo@bell.net> wrote:
EA: "As this sequence needs a lot of backtracking, we don't guarantee the accuracy of the last 79 integers of the 1079-term b-file."
This (and the fact that Neil approved it) surprises me since the OEIS style sheet suggests that (for sequences with conjectured terms) "we give the known terms (up to the first gap) in a b-file, and all the terms - with gaps, question marks, or ranges for the uncertain terms - in an a-file". _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun