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 A277334 #14 Oct 24 2016 01:56:37 %S A277334 1,2,3,5,7,9,11,13,15,17,19,21,23,25,29,31,33,35,37,39,41,43,47,49,51, %T A277334 53,55,57,59,61,65,67,69,71,73,75,77,79,83,85,87,89,91,93,95,97,101, %U A277334 103,105,107,109,111,113,115,119,121,123,127,129,131,133,137,139,141,143,145,147,149,151,155,157,159,161,163,165,167,169 %N A277334 Numbers n, that apart from 2 are all odd and for which n/(largest prime dividing n) is squarefree. %C A277334 In other words, after 1 and 2, such odd numbers that only the largest prime factor in their prime factorization may have exponent 1 or 2, while all lesser prime factors occur at most once. %H A277334 Antti Karttunen, <a href="/A277334/b277334.txt">Table of n, a(n) for n = 1..10000</a> %p A277334 with(numtheory): A277334_list := n -> seq(`if`(i=2 or (i::odd and issqrfree(i/ max(factorset(i)))),i,NULL),i=1..n): A277334_list(169); # _Peter Luschny_, Oct 23 2016 %o A277334 (Scheme, with _Antti Karttunen_'s IntSeq-library) %o A277334 (define A277334 (MATCHING-POS 1 1 (lambda (n) (and (or (= 2 n) (not (even? n))) (not (zero? (A008683 (A052126 n)))))))) %Y A277334 Disjoint union of A056911 and A129598(A056911(n)). %Y A277334 Cf. A005117, A008683, A052126. %Y A277334 Cf. A277332 (permutation of this sequence). %Y A277334 Differs from A091377 for the first time at n=36, where a(36)=75, while A091377(36)=77. %K A277334 nonn %O A277334 1,2 %A A277334 _Antti Karttunen_, Oct 12 2016