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 A124728 #10 Jul 10 2025 19:39:23
%S A124728 4023,7314,9162,12122,12123,16674,19434,19940,23874,24723,29094,33234,
%T A124728 35124,35125,39234,42182,42183,44163,45175,46988,49147,51793,52854,
%U A124728 52855,54584,54585,54663,58375,63594,64074,64075,64323,64491,64712
%N A124728 Numbers k such that k, k+1, k+2 and k+3 are products of 4 primes.
%C A124728 Subset of A045940 Numbers m such that factorizations of m through m+3 have same number of primes (including multiplicities). Cf. A124057, A124729 Numbers k such that k, k+1, k+2 and k+3 are products of exactly 3,5 primes. There are no numbers k such that k, k+1, k+2 and k+3 are products of exactly 6 primes(?)
%H A124728 D. W. Wilson, <a href="/A124728/b124728.txt">Table of n, a(n) for n = 1..10000</a>
%e A124728 4023=3^3*149, 4024=2^3*503, 4025=5^2*7*23, 4026=2*3*11*61 (all products of 4 primes).
%t A124728 Transpose[Select[Partition[Range[65000],4,1],Union[PrimeOmega[#]] == {4}&]] [[1]] (* _Harvey P. Dale_, Nov 01 2011 *)
%Y A124728 Cf. A045940, A124057, A124729.
%K A124728 nonn
%O A124728 1,1
%A A124728 _Zak Seidov_, Nov 05 2006