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.

A373033 a(0) = 5. For n >= 1, a(n) = a(n-1) converted to base 4 and interpreted in base 10.

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%I A373033 #24 May 22 2024 12:55:44
%S A373033 5,11,23,113,1301,110111,122320133,13102213110011,
%T A373033 2332222120300201203323,133212320111123130111021311111121323,
%U A373033 12122133133313032110200332320320202022333020121323230212223,1323212003321221211122101013133003222123113122111221033300222032132012202011331212030120003001333
%N A373033 a(0) = 5. For n >= 1, a(n) = a(n-1) converted to base 4 and interpreted in base 10.
%C A373033 a(n) is prime for n = 0, 1, 2, 3, 4. What is the next n for which a(n) is prime?
%H A373033 Paolo Xausa, <a href="/A373033/b373033.txt">Table of n, a(n) for n = 0..15</a>
%H A373033 Grant Sanderson, <a href="https://www.youtube.com/watch?v=NOCsdhzo6Jg">How They Fool Ya (live) | Math parody of Hallelujah</a>, 3Blue1Brown YouTube video, 2023.
%F A373033 From _Jianing Song_, May 22 2024: (Start)
%F A373033 a(n+1) = A007090(a(n)).
%F A373033 As A007090(n+1) = A007090(n) + 1 if n is not congruent to 3 modulo 4, and all terms of A023378 are even, we have a(n) = A023378(n) + 1 by induction. (End)
%e A373033 5        -->        11        -->        23 ...
%e A373033   base 10 to base 4    base 10 to base 4
%t A373033 NestList[FromDigits[IntegerDigits[#, 4]] &, 5, 11]
%Y A373033 Cf. A007090, A023378, A065722.
%K A373033 nonn,base,easy
%O A373033 0,1
%A A373033 _Paolo Xausa_, May 20 2024