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 A242243 #5 May 17 2014 03:47:24 %S A242243 15,33,187,309,559,1411,1897,2263,2869,3543,6979,10717,11559,11995, %T A242243 22353,32953,39009,54529,57363,58333,66313,77011,80383,113917,120759, %U A242243 124969,147079,158011,167701,175983,177673,237661,241581,253519,299767,310813,376387,381309 %N A242243 Semiprimes sp of the form p^2 + q + 1 where p and q are consecutive primes. %H A242243 K. D. Bajpai, <a href="/A242243/b242243.txt">Table of n, a(n) for n = 1..5970</a> %e A242243 a(1) = 15 = 3^2 + 5 + 1 = 3 * 5 is semiprime, 3 and 5 are consecutive primes. %e A242243 a(2) = 33 = 5^2 + 7 + 1 = 3 * 11 is semiprime, 5 and 7 are consecutive primes. %p A242243 with(numtheory): A242243:= proc()local k ; k:=(ithprime(x)^2+ithprime(x+1)+1);if bigomega(k)=2 then RETURN (k); fi;end: seq(A242243 (),x=1..500); %t A242243 Select[Table[Prime[n]^2 + Prime[n + 1] + 1, {n, 500}], PrimeOmega[#] == 2 &] %Y A242243 Cf. A000040, A001358, A045636, A145292, A228183. %K A242243 nonn %O A242243 1,1 %A A242243 _K. D. Bajpai_, May 09 2014