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 A308730 #14 Jul 06 2019 06:09:07 %S A308730 2,3,7,89,31,13367,127,2099863,178481 %N A308730 Smallest prime p for which n is the least number of 1's in the base-2 representation of a multiple of p. %C A308730 It is not known if a(n) actually exists for all n. If there are infinitely many Mersenne primes, then a(n) is defined for infinitely many n. %C A308730 The corresponding multipliers for n = 1,2,...,7 are 1,1,1,1,1,5,1,1,1. (Computations done by Leon Witzman.) %H A308730 K. B. Stolarsky, <a href="http://matwbn.icm.edu.pl/ksiazki/aa/aa38/aa3825.pdf">Integers whose multiples have anomalous digital frequencies</a>, Acta Arithmetica 38 (1980), 117-128, DOI:<a href="https://doi.org/10.4064/aa-38-2-117-128">10.4064/aa-38-2-117-128</a>. %F A308730 A086342(a(n)) = n. - _Rémy Sigrist_, Jul 06 2019 %Y A308730 Cf. A086342, A278966. %K A308730 nonn,base,more %O A308730 1,1 %A A308730 _Jeffrey Shallit_, Jun 20 2019