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 A379566 #14 Dec 26 2024 10:15:28 %S A379566 2,2,7,14,40,103,278,783,2172,6191,17701,51205,149149,436932,1287378, %T A379566 3809498,11321211,33764868,101029398,303175579,912147300,2750855002, %U A379566 8313825647,25176031558,76375623757,232082001064,706304629714,2152571584249,6568923555719 %N A379566 Number of n-digit numbers that have exactly 3 divisors. %F A379566 a(n) = A122121(n) - A122121(n-1). %Y A379566 Column k=3 of A284398. %Y A379566 Cf. A001248, A006880, A122121. %K A379566 nonn,base %O A379566 1,1 %A A379566 _Seiichi Manyama_, Dec 26 2024 %E A379566 a(18)-a(29) from _Seiichi Manyama_ using A122121 data, Dec 26 2024