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 A075430 #26 May 07 2025 10:49:26
%S A075430 2,3,5,7,11,13,23,29,31,37,41,43,47,59,61,67,71,73,79,83,101,103,107,
%T A075430 109,113,131,137,139,157,167,173,179,181,191,193,211,223,227,229,239,
%U A075430 257,263,277,281,283,311,313,317,331,347,353,359,367,373,383,389,397
%N A075430 Primes with a squarefree neighbor.
%H A075430 Amiram Eldar, <a href="/A075430/b075430.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Enrique Pérez Herrero)
%e A075430 a(3) = 5 because 6 (the number above) is squarefree.
%e A075430 a(13) = 47 because 46 (the number below) is squarefree.
%e A075430 53 is not in the sequence because both 52 and 54 have squares among their divisors.
%t A075430 Select[Prime[Range[100]], Or @@ SquareFreeQ /@ (# + {-1, 1}) &] (* _Amiram Eldar_, May 07 2025 *)
%o A075430 (Sage) def is_A075430(n): return is_prime(n) and (is_squarefree(n-1) or is_squarefree(n+1)) # _D. S. McNeil_, Jan 16 2011
%o A075430 (PARI) isok(p) = isprime(p) && (issquarefree(p-1) || issquarefree(p+1)); \\ _Michel Marcus_, Feb 20 2023
%Y A075430 Union of A039787 and A049097.
%Y A075430 Complement of A075432 in A000040.
%Y A075430 Cf. A005117.
%K A075430 nonn
%O A075430 1,1
%A A075430 _Reinhard Zumkeller_, Sep 15 2002