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 A280509 #14 Dec 26 2024 10:15:56 %S A280509 1,1,2,1,1,2,1,1,3,1,1,2,1,1,2,1,1,3,1,1,2,1,4,2,1,1,1,1,2,2,1,1,2,1, %T A280509 1,3,1,1,1,1,1,2,1,1,2,4,1,2,1,1,2,1,1,1,1,1,1,2,1,2,1,1,3,1,1,2,1,1, %U A280509 5,1,2,3,1,1,3,1,1,1,1,1,2,1,1,2,1,1,1,1,1,2,1,4,1,1,2,2,1,1,3,1,1,2,1,1,2,1,2,1,1,1,1,1,4,1,1,2,1,1,2,2 %N A280509 a(n) = A051064(A246200(n)); 3-adic valuation of A057889(3*n). %H A280509 Antti Karttunen, <a href="/A280509/b280509.txt">Table of n, a(n) for n = 1..10921</a> %H A280509 Nicholas John Bizzell-Browning, <a href="https://bura.brunel.ac.uk/handle/2438/29960">LIE scales: Composing with scales of linear intervallic expansion</a>, Ph. D. Thesis, Brunel Univ. (UK, 2024). See p. 73. %H A280509 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %F A280509 a(n) = A007949(A057889(3*n)). %F A280509 a(n) = A051064(A246200(n)). %o A280509 (Scheme) (define (A280509 n) (A051064 (A246200 n))) %o A280509 (PARI) %o A280509 A030101(n) = if(n<1,0,subst(Polrev(binary(n)),x,2)); %o A280509 A057889(n) = if(!n,n,A030101(n/(2^valuation(n,2))) * (2^valuation(n, 2))); %o A280509 A280509(n) = valuation(A057889(3*n),3); \\ _Antti Karttunen_, Dec 26 2024 %Y A280509 Cf. A007949, A057889, A246200, A280508. %Y A280509 Differs from A051064 for the first time at n=23, where a(23) = 4, while A051064(23) = 1. %Y A280509 Cf. also A265331. %K A280509 nonn,base %O A280509 1,3 %A A280509 _Antti Karttunen_, Jan 09 2017