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 A085089 #11 Jul 17 2019 07:21:43 %S A085089 1,2,2,3,3,4,4,5,5,5,5,6,6,6,6,7,7,7,7,7,7,7,7,8,8,8,8,8,8,9,9,10,10, %T A085089 10,10,11,11,11,11,11,11,11,11,11,11,11,11,12,12,12,12,12,12,12,12,12, %U A085089 12,12,12,13,13,13,13,14,14,14,14,14,14,14,14,15,15,15,15,15,15,15,15,15 %N A085089 Number of distinct prime signatures arising up to n. %H A085089 Alois P. Heinz, <a href="/A085089/b085089.txt">Table of n, a(n) for n = 1..65536</a> %o A085089 (PARI) A085089(n)=#Set(apply(t->vecsort(factor(t)[,2]), [1..n])) \\ Not very efficient for large n > 10^5, but very quick up to the point where stack overflow occurs. - _M. F. Hasler_, Jul 16 2019 %Y A085089 Cf. A025487. %Y A085089 Cf. A025488(n) = a(2^n); A124832 (table of the distinct prime signatures in the order they occur). %K A085089 easy,nonn %O A085089 1,2 %A A085089 _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jul 02 2003 %E A085089 More terms from _Ray Chandler_, Aug 17 2003