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 A240476 #17 Apr 29 2014 02:03:36 %S A240476 3,5,7,11,13,23,29,31,37,41,43,47,59,61,67,71,73,79,83,97,101,103,107, %T A240476 109,113,127,131,137,139,149,151,157,167,173,179,181,191,193,211,223, %U A240476 227,229,239,241,257,263,277,281,283,311,313,317,331,347,349,353 %N A240476 Primes that are not midway between the closest flanking squarefree numbers. %C A240476 Primes for which the corresponding A240473(m) is not equal to A240474(m). %C A240476 Primes not equal to the average of the closest flanking squarefree numbers. %C A240476 Primes not equal to the average of three consecutive squarefree numbers. %C A240476 Complement of A240475 relative to A000040. %H A240476 Chris Boyd, <a href="/A240476/b240476.txt">Table of n, a(n) for n = 1..10000</a> %e A240476 29 is a term because it is not midway between the closest flanking squarefree numbers 26 and 30. %e A240476 On the other hand, 19 is not a term because it is midway between the closest flanking squarefree numbers 17 and 21. %o A240476 (PARI) forprime(p=1,353,forstep(j=p-1,1,-1,if(issquarefree(j),L=j;break));for(j=p+1,2*p,if(issquarefree(j),G=j;break));if(G-p!=p-L,print1(p", "))) %Y A240476 Cf. A000040, A075430, A075432, A240473, A240474, A240475 %K A240476 nonn %O A240476 1,1 %A A240476 _Chris Boyd_, Apr 06 2014