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 A088380 #13 Feb 12 2025 11:55:57 %S A088380 1,2,3,4,5,6,7,8,9,11,13,15,17,19,21,23,25,27,29,31,35,37,41,43,47,49, %T A088380 53,55,59,61,65,67,71,73,77,79,83,85,89,91,95,97,101,103,107,109,113, %U A088380 115,119,121,125,127,131,133,137,139,143,149,151,157,161,163,167,169 %N A088380 Numbers not exceeding the cube of their smallest prime factor. %C A088380 a(n) <= A020639(a(n))^3 = A088378(a(n)); complement of A088381; %C A088380 a(n) < A088381(k) for n <= 28, a(n) > A088381(k) for n > 28. %H A088380 Reinhard Zumkeller, <a href="/A088380/b088380.txt">Table of n, a(n) for n = 1..10000</a> %t A088380 Select[Range[200],#<=FactorInteger[#][[1,1]]^3&] (* _Harvey P. Dale_, Apr 28 2022 *) %o A088380 (Haskell) %o A088380 a088380 n = a088382_list !! (n-1) %o A088380 a088380_list = [x | x <- [1..], x <= a020639 x ^ 3] %o A088380 -- _Reinhard Zumkeller_, Feb 06 2015 %Y A088380 Cf. A000430, A088382, A020639, A088378, A088381. %Y A088380 Positions of numbers less than 4 in A307908. %K A088380 nonn %O A088380 1,2 %A A088380 _Reinhard Zumkeller_, Sep 28 2003