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 A136743 #6 Feb 16 2025 08:33:07 %S A136743 2,4,3,5,1,1,5,2,5,6,5,5,3,2,1,2,5,3,6,6,3,6,3,6,1,2,6,1,5,6,6,6,4,4, %T A136743 1,6,4,5,6,4,1,1,5,5,2,1,6,3,4,5,6,7,4,6,1,1,6,4,7,6,6,6,3,7,1,2,6,1, %U A136743 5,2,1,7,6,3,7,1,1,5,3,5,8,5,1,2,4,6,2,1,6,3,6,7,4,7,4,1,2,2,6,1,6,6,2,6,5 %N A136743 Number of prime factors in the n-th run of squarefree numbers. %C A136743 a(n) = A001221(A136742(n)) = A001222(A136742(n)); %C A136743 a(A136744(n)) = n and a(m) <> n for m < A136744(n). %H A136743 R. Zumkeller, <a href="/A136743/b136743.txt">Table of n, a(n) for n = 1..1000</a> %H A136743 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Squarefree.html">Squarefree</a> %F A136743 a(n) = SUM(A001221(A072284(n)+k): 0<=k < A120992(n)). %e A136743 a(10)=A001221(A136742(10))=A001221(39270)=A001221(2*3*5*7*11*17)=6. %Y A136743 Cf. A005117. %K A136743 nonn %O A136743 1,1 %A A136743 _Reinhard Zumkeller_, Jan 20 2008