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 A211997 #43 Nov 07 2023 03:15:28 %S A211997 2,3,7,23,31,127,127,383,991,2039,3583,6143,8191,63487,63487,129023, %T A211997 131071,522239,524287,1966079,4128767,14680063,14680063,33546239, %U A211997 67108351,201064447,260046847,536739839,1073479679,2147483647,2147483647,8581545983,16911433727,32212254719 %N A211997 Smallest prime with at least n 1's when written in binary. %C A211997 In contrast to the more vague statement in A061712, the existence of every term of this sequence follows from the Sierpinski theorems (see reference, point 28). %D A211997 Ernst Trost, Primzahlen, Birkhäuser-Verlag, 1953. %F A211997 a(n) <= A061712(n). %Y A211997 Cf. A000120, A061712. %K A211997 nonn,base %O A211997 1,1 %A A211997 _Vladimir Shevelev_ and _Peter J. C. Moses_, Oct 25 2012