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 A128302 #25 Apr 18 2025 21:41:06
%S A128302 1,5,30,82,328,551,1243,1763,3112,6276,7619,12972,17615,20322,26514,
%T A128302 37977,52220,57703,76200,90701,98470,124541,144229,177395,229275,
%U A128302 258410,273908,306750,324149,360724,510225,559384,638657,666743,819645,852588
%N A128302 The indices of cubes (of primes) in the 3-almost primes.
%C A128302 the primepi function might be used to find terms. But it is expensive for larger numbers so then one might use A335331 to ease finding primepi(m) for larger m. - _David A. Corneth_, Apr 13 2025
%H A128302 Amiram Eldar, <a href="/A128302/b128302.txt">Table of n, a(n) for n = 1..590</a>
%H A128302 David A. Corneth, <a href="/A128302/a128302.gp.txt">PARI program</a>
%F A128302 A014612(a(n)) = A030078(n) = A000040(n)^3.
%e A128302 a(4) = 82 as 343 = 7^3 = prime(4)^3, the fourth cube in the 3-almost primes, is the eighty-second 3-almost prime.
%t A128302 Position[Select[Range[10^6], PrimeOmega[#] == 3 &], _?(PrimeNu[#] == 1 &)] // Flatten (* _Amiram Eldar_, Apr 13 2025 *)
%o A128302 (PARI) list(lim) = {my(f, c); for(k = 1, lim, f = factor(k); if(bigomega(f) == 3, c++; if(omega(f) == 1, print1(c, ", "))));} \\ _Amiram Eldar_, Apr 13 2025
%o A128302 (PARI) \\ See Corneth link
%Y A128302 Cf. A000040, A014612, A030078, A128301, A128303, A335331.
%K A128302 nonn
%O A128302 1,2
%A A128302 _Rick L. Shepherd_, Feb 25 2007