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 A077067 #22 Mar 08 2025 06:00:51 %S A077067 3,6,14,30,38,42,62,74,102,110,114,138,158,174,182,194,230,258,278, %T A077067 282,314,318,354,374,390,398,402,410,422,434,458,462,510,542,570,602, %U A077067 614,618,642,654,662,674,678,710,734,758,762,770,798,822,830,854,858,878 %N A077067 Squarefree numbers of the form prime + 1. %H A077067 Amiram Eldar, <a href="/A077067/b077067.txt">Table of n, a(n) for n = 1..10000</a> %F A077067 A077066(a(n)) = a(n). %F A077067 a(n) = A049097(n)+1. - _Zak Seidov_, Aug 15 2006 %e A077067 A005117(28) = 42 = 2*3*7 is a term as 42 = A000040(13) + 1 = 41+1. %t A077067 Select[Prime[Range[200]]+1,SquareFreeQ] (* _Harvey P. Dale_, Aug 20 2017 *) %o A077067 (PARI) isok(n) = issquarefree(n) && isprime(n-1); \\ _Michel Marcus_, Mar 22 2016 %o A077067 (PARI) lista(nn) = forprime(p=2, nn, if (issquarefree(p+1), print1(p+1, ", "))); \\ _Michel Marcus_, Mar 22 2016 %Y A077067 Cf. A000040, A005117, A008864, A049097, A077064, A077066. %K A077067 nonn %O A077067 1,1 %A A077067 _Reinhard Zumkeller_, Oct 23 2002