%I #5 Apr 04 2016 13:29:30
%S 2,3,5,10,13,20,33,60,89,109,116,138,144,152,182,189,212,223,253,258,
%T 297,320,336,350,353,375,390,418,422,487,492,498,501,549,567,579,592,
%U 616,654,671,704,755,799,800,812,826,874,893,917,921,948,951,957,967
%N Numbers n such that prime(n)*prime(n+1) - 1 is semiprime.
%H Ray Chandler, <a href="/A103746/b103746.txt">Table of n, a(n) for n = 1..10000</a>
%e prime(10)*prime(11) - 1 = 29*31 - 1 = 898 = 2*449, hence 10 is a term.
%o (PARI) for(n=1,1000,if(bigomega(prime(n)*prime(n+1)-1)==2,print1(n,",")))
%Y Cf. A001358, A006881, A103533.
%K nonn,easy
%O 1,1
%A _Klaus Brockhaus_, Mar 29 2005