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 A124057 #19 Feb 05 2017 18:49:32
%S A124057 602,603,1083,2012,2091,2522,2523,2524,2634,2763,3243,3355,4202,4203,
%T A124057 4921,4922,4923,5034,5035,5132,5203,5282,5283,5785,5882,5954,5972,
%U A124057 6092,6212,6476,6962,6985,7730,7731,7945,8393,8825,8956,8972,9188,9482,10011
%N A124057 Numbers n such that n, n+1, n+2 and n+3 are products of exactly 3 primes.
%C A124057 n such that n, n+1, n+2 and n+3 are 3-almost primes. Subset of A113789 Numbers n such that n, n+1 and n+2 are products of exactly 3 primes. A067813 has some runs of up to 7 consecutive 3-almost primes (i.e. starting 211673). But there cannot be 8 consecutive 3-almost primes, as every run of 8 consecutive positive integers contains exactly one multiple of 8 = 2^3 and only 8 of all positive multiples of 8 is a 3-almost prime (i.e. all larger multiples have at least 4 prime factors, with multiplicity).
%C A124057 A subset of A045940. - _Zak Seidov_, Nov 05 2006
%H A124057 D. W. Wilson, <a href="/A124057/b124057.txt">Table of n, a(n) for n = 1..10000</a>
%F A124057 n, n+1, n+2 and n+3 are all elements of A014612. n and n+1 are elements of A113789.
%e A124057 a(1) = 602 because 602 = 2 * 7 * 43 and 603 = 3^2 * 67 and 604 = 2^2 * 151 and 605 = 5 * 11^2 are all 3-almost primes.
%e A124057 a(2) = 603 because 603 = 3^2 * 67 and 604 = 2^2 * 151 and 605 = 5 * 11^2 and 606 = 2 * 3 * 101 are all 3-almost primes.
%e A124057 a(3) = 1083 because 1083 = 3 * 19^2 and 1084 = 2^2 * 271 and 1085 = 5 * 7 * 31 and 1086 = 2 * 3 * 181 are all 3-almost primes.
%e A124057 a(4) = 2012 because 2012 = 2^2 * 503, 2013 = 3 * 11 * 61, 2014 = 2 * 19 * 53, 2015 = 5 * 13 * 31.
%e A124057 a(5) = 2091 because 2091 = 3 * 17 * 41, 2092 = 2^2 * 523, 2093 = 7 * 13 * 23, 2094 = 2 * 3 * 349.
%p A124057 with(numtheory): a:=proc(n) if bigomega(n)=3 and bigomega(n+1)=3 and bigomega(n+2)=3 and bigomega(n+3)=3 then n else fi end: seq(a(n),n=1..15000); # _Emeric Deutsch_, Nov 07 2006
%t A124057 okQ[{a_,b_,c_,d_}]:=Union[{a,b,c,d}]=={3}; Flatten[Position[Partition[ PrimeOmega[ Range[11000]],4,1],_?(okQ)]] (* _Harvey P. Dale_, Sep 23 2012 *)
%o A124057 (PARI) is(n)=if(!isprime((n+3)\4), return(0)); for(k=n,n+3, if(bigomega(k)!=3, return(0))); 1 \\ _Charles R Greathouse IV_, Feb 05 2017
%o A124057 (PARI) list(lim)=my(v=List(),u=v,t); forprime(p=2,lim\4, forprime(q=2,min(lim\(2*p),p), t=p*q; forprime(r=2,min(lim\t,q), listput(u,t*r)))); u=Set(u); for(i=4,#u, if(u[i]-u[i-3]==3, listput(v,u[i-3]))); Vec(v) \\ _Charles R Greathouse IV_, Feb 05 2017
%Y A124057 Cf. A000040, A014612, A056809, A067813, A113789, A045940.
%K A124057 easy,nonn
%O A124057 1,1
%A A124057 _Jonathan Vos Post_, Nov 03 2006
%E A124057 More terms from _Zak Seidov_, Nov 05 2006
%E A124057 More terms from _Emeric Deutsch_, Nov 07 2006