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.
a(4)=602 because 602 is the start of a record breaking run of 5 consecutive integers (602 to 606) each having 3 prime factors; i.e. bigomega(n)=A001222(n)=3 for n = 602, ..., 606.
bigomega[n_] := Plus@@Last/@FactorInteger[n]; For[n=1; m=l=0, True, n++, If[bigomega[n]==3, l++, If[l>m, m=l; Print[n-l, " ", l]]; l=0]]
Module[{nn=8,po},po=PrimeOmega[Range[5000000]];Flatten[Table[ SequencePosition[ po,PadRight[{},n,3],1],{n,nn}],1]][[All,1]]//Union (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 14 2019 *)
show(lim)=my(was,r,ct); forfactored(n=2, lim\1+1, is=vecsum(n[2][, 2])==3; if(is, ct++; if(ct>r, r=ct; print(r" "n[1]-r+1)),ct=0)) \\ Charles R Greathouse IV, Jun 26 2019
a(3) = 18241 is a term because 18241 = 17 * 29 * 37 18242 = 2 * 7 * 1303 18243 = 3^2 * 2027 18244 = 2^2 * 4561 18245 = 5 * 41 * 89 18246 = 2 * 3 * 3041 are all products of 3 primes (counted with multiplicity).
R:= NULL: count:= 0: p:= 1:
while count < 100 do
p:= nextprime(p);
x:= 4*p;
if andmap(t -> numtheory:-bigomega(t)=3, [x-2,x-1,x+1,x+2]) then
if numtheory:-bigomega(x-3) = 3 then R:= R, x-3; count:= count+1; fi;
if numtheory:-bigomega(x+3) = 3 then R:= R, x-2; count:= count+1; fi;
fi;
od:
R;
s = {}; Do[If[{3, 3, 3, 3, 3, 3} == PrimeOmega[Range[k, k + 5]],
AppendTo[s, k]], {k, 1000000}]; s
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