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 A110893 #5 Jan 31 2017 14:27:07 %S A110893 16,24,36,40,54,56,60,64,81,84,88,90,96,100,104,126,132,135,136,140, %T A110893 144,150,152,156,160,184,189,196,198,204,210,216,220,224,225,228,232, %U A110893 234,240,248,250,260,276,294,296,297,306,308,315,324,328,330,336,340,342 %N A110893 Numbers with a semiprime number of prime divisors (counted with multiplicity). %C A110893 Below 256 = 2^8 this is identical to A067028 (Numbers with a composite number of prime factors, counted with multiplicity). %H A110893 Charles R Greathouse IV, <a href="/A110893/b110893.txt">Table of n, a(n) for n = 1..10000</a> %F A110893 a(n) such that A001222(a(n)) is an element of A001358. a(n) such that bigomega(a(n)) is an element of A001358. Union[4-almost primes(A014613), 6-almost primes(A046306), 9-almost primes(A046312), 10-almost primes(A046314), 14-almost primes(A069275), 15-almost primes(A069276), 21-almost primes, 22-almost primes, 25-almost primes, 26-almost primes, ...] %o A110893 (PARI) is(n)=n>9 && bigomega(bigomega(n))==2 \\ _Charles R Greathouse IV_, Jan 31 2017 %Y A110893 Cf. A000040, A001222, A001358, A014613, A046306, A046312, A046314, A063989, A067028, A069276. %K A110893 easy,nonn %O A110893 1,1 %A A110893 _Jonathan Vos Post_, Sep 20 2005