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 A171525 #9 May 13 2013 01:49:12 %S A171525 1,1,1,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83, %T A171525 89,97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173, %U A171525 179,181,191,193,197,199,211,223,227 %N A171525 Numerator of (n-th noncomposite/n). %C A171525 Numerator of (A008578(n)/n). a(1)= a(2) = a(3) = 1, a(n) = A008578(n) = A000040(n-1) for n >= 4. %o A171525 (PARI) a(n)=if(n>3,prime(n-1),1) \\ _Charles R Greathouse IV_, Aug 22 2011 %K A171525 nonn,easy %O A171525 1,4 %A A171525 _Jaroslav Krizek_, Dec 11 2009