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 A103767 #7 Mar 15 2015 14:43:11 %S A103767 6,10,29,42,44,55,57,102,104,111,120,136,174,184,257,269,308,325,327, %T A103767 401,426,504,514,565,571,594,595,652,717,755,864,882,901,907,985,1014, %U A103767 1074,1134,1141,1156,1198,1301,1327,1346,1362,1654,1670,1674,1778,1897 %N A103767 Numbers n such that prime(n)*prime(n+1)*prime(n+2) - 1 is semiprime. %H A103767 Harvey P. Dale, <a href="/A103767/b103767.txt">Table of n, a(n) for n = 1..1000</a> %e A103767 prime(10)*prime(11)*prime(12) - 1 = 29*31*37 - 1 = 33262= 2*16631, hence 10 is %e A103767 a term. %t A103767 PrimePi/@Transpose[Select[Partition[Prime[Range[2000]],3,1], PrimeOmega[ Times@@#-1]==2&]][[1]] (* _Harvey P. Dale_, Mar 15 2015 *) %o A103767 (PARI) for(n=1,1900,if(bigomega(prime(n)*prime(n+1)*prime(n+2)-1)==2,print1(n,","))) %Y A103767 Cf. A001358, A006881, A103614, A103746. %K A103767 nonn,easy %O A103767 1,1 %A A103767 _Klaus Brockhaus_, Mar 29 2005