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 A049233 #29 Aug 10 2024 22:34:04
%S A049233 3,5,11,13,17,19,29,31,37,41,53,59,67,71,83,89,101,103,107,109,113,
%T A049233 127,131,137,139,149,157,163,179,181,191,193,197,199,211,227,229,233,
%U A049233 239,251,257,263,269,271,281,283,293,307,311,317,337,347,353,379,383,389
%N A049233 Primes p such that p + 2 is squarefree.
%C A049233 A001359 (lesser of twin primes) is a subsequence. - _Michel Marcus_, Aug 10 2018
%C A049233 This sequence is infinite and its relative density in the sequence of primes is equal to 2 * Product_{p prime} (1-1/(p*(p-1))) = 2 * A005596 = 0.747911... (Mirsky, 1949). - _Amiram Eldar_, Dec 29 2020
%H A049233 Robert Israel, <a href="/A049233/b049233.txt">Table of n, a(n) for n = 1..10000</a>
%H A049233 Denis Xavier Charles, <a href="http://pages.cs.wisc.edu/~cdx/Sieve.pdf">Sieve Methods</a>, Master's Thesis, 2000, p. 93.
%H A049233 Leon Mirsky, <a href="https://www.jstor.org/stable/2305811">The number of representations of an integer as the sum of a prime and a k-free integer</a>, The American Mathematical Monthly, Vol. 56, No. 1 (1949), pp. 17-19.
%p A049233 A049233:=n->`if`(isprime(n) and numtheory[issqrfree](n+2), n, NULL): seq(A049233(n), n=1..600); # _Wesley Ivan Hurt_, Nov 22 2015
%t A049233 Select[Prime[Range[100]], SquareFreeQ[#+2]&] (* _Jean-François Alcover_, Nov 22 2015 *)
%o A049233 (PARI) isok(p) = isprime(p) && issquarefree(p+2); \\ _Michel Marcus_, Dec 31 2013
%Y A049233 Cf. A001359, A005117, A005596.
%K A049233 nonn
%O A049233 1,1
%A A049233 _Labos Elemer_
%E A049233 Definition simplified by _Michel Marcus_, Dec 31 2013