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 A129473 #3 Mar 31 2012 13:48:24
%S A129473 15913,18541,22921,36353,47741,49201,52267,55333,60589,64969,66137,
%T A129473 66721,69203,72707,73291,74167,75773,78401,79861,80737,82051,84533,
%U A129473 90227,90373,95191,95483,95629,97673,99133,101323,103951,104681,104827
%N A129473 Primes p of Erdos-Selfridge class 5+ with largest prime factor of p+1 not of class 4+.
%C A129473 See A129470
%e A129473 a(1) = 15913 = -1+2*73*109 is a prime of class 5+ since 73 is of class 4+, but the largest divisor of 15913+1 is 109 which is only of class 2+.
%o A129473 (PARI) class(n,s=1)={n=factor(n+s)[,1];if(n[ #n]<=3,1,for(i=2,#n,n[1]=max(class(n[i],s)+1,n[1]));n[1])}; A129473(n=100,p=1,a=[])={ local(f); while( #a<n, until( f[ #f] > 3 & 4 > class(f[ #f]), f=factor(1+p=nextprime(p+1))[,1]); forstep( i=#f-1,2,-1, if( 5 < f[1] = max( f[1],1+class( f[i] )), next(2))); if( f[1] == 5, a=concat(a,p); /*print(#a," ",p)*/)); a}
%Y A129473 Subsequence of A129470; see also A129471-A129472, A129477-A129478, A129469, A005113, A005105-A005108, A081633.
%K A129473 easy,nonn
%O A129473 1,1
%A A129473 _M. F. Hasler_, Apr 17 2007