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 A064186 #19 Jan 03 2020 21:19:19 %S A064186 3,5,8,9,10,13,17,20,22,24,26,34,39,53,59,61,63,69,70,76,80,87,97,99, %T A064186 103,124,130 %N A064186 Numbers n such that n!+1 and n!-1 have the same number of prime divisors (with repetition). %C A064186 200, 236, 392 and 634 are terms. - _Chai Wah Wu_, Jan 03 2020 %t A064186 Select[Range[30], PrimeOmega[#! - 1] == PrimeOmega[#! + 1] &] (* _Amiram Eldar_, Dec 01 2019 *) %o A064186 (PARI) for(n=2,100, if(bigomega(n!+1)==bigomega(n!-1),print(n))) %Y A064186 Cf. A054990, A054991. %K A064186 more,nonn %O A064186 1,1 %A A064186 _Jason Earls_, Sep 20 2001 %E A064186 a(15)-a(25) from _Donovan Johnson_, Mar 09 2008 %E A064186 Offset corrected by _Donovan Johnson_, Jul 11 2013 %E A064186 a(26)-a(27) from _Amiram Eldar_, Dec 01 2019