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 A067386 #24 May 08 2022 16:58:39 %S A067386 3,11,13,19,23,37,47,53,73,97,107,131,139,163,181,193,229,239,281,307, %T A067386 311,349,373,379,383,409,439,443,487,491,521,577,599,601,617,619,643, %U A067386 683,701,709,727,739,743,761,811,821,827,829,853,863,881,883,919,937 %N A067386 Primes p such that p+1 and p-1 have the same number of distinct prime factors. %H A067386 Charles R Greathouse IV, <a href="/A067386/b067386.txt">Table of n, a(n) for n = 1..10000</a> %p A067386 q:= p-> isprime(p) and nops(ifactors(p+1)[2])=nops(ifactors(p-1)[2]): %p A067386 select(q, [$1..1000])[]; # _Alois P. Heinz_, May 08 2022 %t A067386 Select[Prime[Range[200]],PrimeNu[#-1]==PrimeNu[#+1]&] (* _Harvey P. Dale_, Jun 28 2020 *) %o A067386 (PARI) is(n)=omega(n-1)==omega(n+1) && isprime(n) \\ _Charles R Greathouse IV_, Sep 14 2015 %Y A067386 Cf. A115103 (same number of prime factors with multiplicity). %K A067386 easy,nonn %O A067386 1,1 %A A067386 _Benoit Cloitre_, Feb 23 2002