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 A210502 #11 Jan 21 2013 15:03:32 %S A210502 1,0,0,1,0,1,0,1,0,0,0,2,2,1,0,0,0,3,0,0,5,0,0,1,3,1,0,0,3,1,0,0,0,0, %T A210502 0,0,2,1,0,0,0,4,0,3,0,0,0,0,0,0,1,0,9,0,0,0,0,0,3,2,0,0,0,0,5,0,0,4, %U A210502 0,2,2,0,0,0,0,0,0,5,3,1,0,5,0,10,0,0,2 %N A210502 a(1) = 1, a(n) = A210501(n) - 1. %C A210502 Number of odd solutions to phi(k) = prime(n) - 1, except k = prime(n). %D A210502 Alexander S. Karpenko, Lukasiewicz's Logics and Prime Numbers, Luniver Press, Beckington, 2006, pp. 52-56. %H A210502 Arkadiusz Wesolowski, <a href="/A210502/b210502.txt">Table of n, a(n) for n = 1..1000</a> %F A210502 a(1) = 1, a(n) = A058339(n) - A210500(n) - 1. %Y A210502 Cf. A000010, A058339, A210500, A210501. %K A210502 nonn %O A210502 1,12 %A A210502 _Arkadiusz Wesolowski_, Jan 20 2013