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 A174801 #3 Mar 30 2012 18:52:39 %S A174801 1,2,3,6,12,18,21,37,44,59,65,78,82,88,100,112,121,122,130,134,151, %T A174801 168,183,191,197,198,203,216,221,231,257,260,273,287,295,301,306,322, %U A174801 347,366,375,378,407,415,422,438,455,459,466,491,521,556,560,574,585,587 %N A174801 Prime(n)+1 is prime or semiprime. %e A174801 a(1)=1 because prime(1)+1=3=prime; a(2)=2 because prime(2)+1=4=semiprime; a(3)=3 because prime(3)+1=6=semiprime; a(4)=6 because prime(6)+1=14=semiprime. %Y A174801 Cf. A000040, A001358. %K A174801 nonn %O A174801 1,2 %A A174801 _Juri-Stepan Gerasimov_, Mar 29 2010 %E A174801 Extended by _Ray Chandler_, Apr 06 2010