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 A379570 #38 May 03 2025 23:51:49
%S A379570 0,10,170,1934,20067,202246,2003991,19674052,192215670,1873532828,
%T A379570 18242642732,177582019015,1728951136938,16840198807124,
%U A379570 164117159854744,1600427660469575,15617400806292160
%N A379570 Number of n-digit numbers that have exactly 8 divisors.
%C A379570 A number has exactly 8 divisors iff it can be expressed as p*q*r, p^3*q, or p^7, where p, q, and r are distinct primes. - _David Radcliffe_, Dec 30 2024
%H A379570 Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/A379570.py">Python program</a>.
%F A379570 Sum_{k=1..n} a(k) = A215218(n) + Sum_{p prime} PrimePi[N/p^3] - PrimePi[N^(1/4)] + PrimePi[N^(1/7)] where N = 10^n. - _David Radcliffe_, Dec 30 2024
%o A379570 (Python) # See LINKS.
%Y A379570 Column k=8 of A284398.
%Y A379570 Cf. A215218.
%K A379570 nonn,more,base
%O A379570 1,2
%A A379570 _Seiichi Manyama_, Dec 26 2024
%E A379570 a(10) from _Giorgos Kalogeropoulos_, Dec 30 2024
%E A379570 a(11)-a(17) from _David Radcliffe_, Jan 01 2025