cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A321020 A hybrid of Kolakoski's sequence A000002 and Golomb's sequence A001462: if A001462(n) is odd replace it with 1, if even with 2.

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%I A321020 #23 Feb 27 2020 23:22:31
%S A321020 1,2,2,1,1,2,2,2,1,1,1,2,2,2,2,1,1,1,1,2,2,2,2,1,1,1,1,1,2,2,2,2,2,1,
%T A321020 1,1,1,1,2,2,2,2,2,2,1,1,1,1,1,1,2,2,2,2,2,2,1,1,1,1,1,1,2,2,2,2,2,2,
%U A321020 2,1,1,1,1,1,1,1,2,2,2,2,2,2,2,1
%N A321020 A hybrid of Kolakoski's sequence A000002 and Golomb's sequence A001462: if A001462(n) is odd replace it with 1, if even with 2.
%C A321020 This is A000002 rewritten so the run lengths are given by A001462.
%C A321020 The companion sequence, A001462 rewritten so the run lengths are given by A000002, seems to be A156253.
%C A321020 Note that Kolakoski's sequence A000002 and Golomb's sequence A001462 have very similar definitions, although the asymptotic behavior of A001462 is well-understood, while that of A000002 is a mystery. The asymptotic behavior of the two hybrids A156253 and A321020 might be worth investigating.
%H A321020 Rémy Sigrist, <a href="/A321020/b321020.txt">Table of n, a(n) for n = 1..25000</a>
%H A321020 N. J. A. Sloane, Coordination Sequences, Planing Numbers, and Other Recent Sequences (II), Experimental Mathematics Seminar, Rutgers University, Jan 31 2019, <a href="https://vimeo.com/314786942">Part I</a>, <a href="https://vimeo.com/314790822">Part 2</a>, <a href="https://oeis.org/A320487/a320487.pdf">Slides.</a> (Mentions this sequence)
%o A321020 (PARI) a = vector(84, k, k); for (i=1, oo, for (j=1, a[i], a[n++] = i; print1 (2-(i%2) ", "); if (n==#a, break(2)))) \\ _Rémy Sigrist_, Nov 12 2018
%Y A321020 Cf. A000002, A001462, A156253.
%K A321020 nonn
%O A321020 1,2
%A A321020 _N. J. A. Sloane_, Nov 11 2018