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 A259559 #17 Nov 29 2015 12:52:28
%S A259559 3,4,10,12,19,29,34,36,45,46,50,61,85,89,91,104,112,117,118,119,129,
%T A259559 130,137,138,143,147,148,158,178,179,181,185,200,202,206,214,220,233,
%U A259559 238,239,244,248,249,258,262,275,299,304,314,333,338,340
%N A259559 Numbers n such that prime(n)-1 and prime(n+1)-1 have the same number of prime factors, including repeats.
%C A259559 Unlike A105403, this sequence appears to be infinite.
%e A259559 The prime factors of prime(10)-1 are 2,2,7 and the prime factors of prime(11)-1 are 2,3,5 and so they have the same number of prime factors, including repeats.
%t A259559 Select[Range@ 360, PrimeOmega[Prime[#] - 1] == PrimeOmega[Prime[# + 1] - 1] &] (* _Michael De Vlieger_, Jul 01 2015 *)
%t A259559 Transpose[SequencePosition[Table[PrimeOmega[Prime[n]-1],{n,400}],{x_,x_}]][[1]] (* The program uses the SequencePosition function from Mathematica version 10 *) (* _Harvey P. Dale_, Nov 29 2015 *)
%o A259559 (PARI) lista(nn) = {forprime(p=2, nn, if (bigomega(p-1)==bigomega(nextprime(p+1)-1), print1(primepi(p), ", ")););} \\ _Michel Marcus_, Jul 01 2015
%Y A259559 Cf. A105403, A259558.
%K A259559 nonn
%O A259559 1,1
%A A259559 _Pratik Koirala_, _Otis Tweneboah_, _Nathan Fox_, _Eugene Fiorini_, Jun 30 2015