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.
%I A305659 #20 Feb 12 2021 12:12:57 %S A305659 1,2,21,212,21011,212022,21200101,2101100202,21202202121, %T A305659 2120012010112,210110211022111,2122111011101222,212001222211110201, %U A305659 21011210220122222102,2101100011201022201221,21202200211121122010012,2120010121200020001020211,210110211001100210002212122 %N A305659 Powers of 2 in base 3/2. %C A305659 a(n) is A305658(n) with n zeros removed at the end, where A305658(n) is powers of 3 in base 3/2. %H A305659 B. Chen, R. Chen, J. Guo, S. Lee et al., <a href="http://arxiv.org/abs/1808.04304">On Base 3/2 and its Sequences</a>, arXiv:1808.04304 [math.NT], 2018. %F A305659 a(n) = A024629(A000079(n)). - _Michel Marcus_, Jun 18 2018 %p A305659 b:= proc(n) `if`(n<1, 0, irem(n, 3, 'q')+b(2*q)*10) end: %p A305659 a:= n-> b(2^n): %p A305659 seq(a(n), n=0..20); # _Alois P. Heinz_, Jun 18 2018 %o A305659 (PARI) f(n) = if( n<1, 0, f(n\3 * 2) * 10 + n%3); %o A305659 a(n) = f(2^n); \\ _Michel Marcus_, Jun 18 2018 %Y A305659 Cf. A024629, A246435, A305658. %K A305659 nonn,base %O A305659 0,2 %A A305659 _Tanya Khovanova_ and PRIMES STEP Senior group, Jun 07 2018 %E A305659 More terms from _Michel Marcus_, Jun 18 2018