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 A115958 #16 Aug 04 2025 20:52:53
%S A115958 930,1110,1230,1290,1410,1590,1770,1806,1830,1974,2010,2130,2190,2226,
%T A115958 2370,2478,2490,2562,2670,2814,2910,2982,3030,3066,3090,3210,3270,
%U A115958 3318,3390,3486,3660,3738,3810,3930,4020,4074,4110,4170,4242,4260,4326,4380
%N A115958 Numbers k having exactly 4 distinct prime factors, the largest of which is greater than or equal to sqrt(k) (i.e., sqrt(k)-rough numbers with exactly 4 distinct prime factors).
%H A115958 Robert Israel, <a href="/A115958/b115958.txt">Table of n, a(n) for n = 1..10000</a>
%e A115958 3660 is in the sequence because it has 4 distinct prime factors (2, 3, 5 and 61) and 61 > sqrt(3660).
%p A115958 with(numtheory): a:=proc(n) if nops(factorset(n))=4 and factorset(n)[4]^2>=n then n else fi end: seq(a(n),n=1..4500);
%t A115958 pf4Q[n_]:=Module[{f=FactorInteger[n]},Length[f]==4 && f[[-1,1]] >= Sqrt[ n]]; Select[Range[5000],pf4Q] (* _Harvey P. Dale_, Sep 13 2017 *)
%Y A115958 Cf. A115956, A115957, A115959, A115960, A115961.
%K A115958 nonn
%O A115958 1,1
%A A115958 _Emeric Deutsch_, Feb 02 2006