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 A128304 #14 Apr 13 2025 03:14:52
%S A128304 1,8,90,385,2556,5138,15590,24646,53993,139199,182476,375363,569617,
%T A128304 691012,991150,1613115,2490040,2849478,4163793,5263838,5888203,
%U A128304 8100907,9886861,13102875,18538021,21816421,23608907,27525519,29659283,34290671
%N A128304 Indices of 4th powers (of primes) in the 4-almost primes.
%H A128304 Amiram Eldar, <a href="/A128304/b128304.txt">Table of n, a(n) for n = 1..99</a> (terms 1..40 from Zak Seidov)
%F A128304 A014613(a(n)) = A030514(n) = A000040(n)^4.
%e A128304 a(3) = 90 as 625 = 5^4 = prime(3)^4, the third 4th power in the 4-almost primes, is the 90th 4-almost prime.
%t A128304 Position[Select[Range[10^6], PrimeOmega[#] == 4 &], _?(PrimeNu[#] == 1 &)] // Flatten (* _Amiram Eldar_, Apr 13 2025 *)
%o A128304 (PARI) list(lim) = {my(f, c); for(k = 1, lim, f = factor(k); if(bigomega(f) == 4, c++; if(omega(f) == 1, print1(c, ", "))));} \\ _Amiram Eldar_, Apr 13 2025
%Y A128304 Cf. A000040, A014613, A030514, A128303, A128305.
%K A128304 nonn
%O A128304 1,2
%A A128304 _Rick L. Shepherd_, Mar 05 2007