%I
%S 15,21,85,265,2761,10129,111001,887161,21047881,210471241,1037836969,
%T 68018232241,361167207241,3312775065961,49691625984361,
%U 1548286451713369,16361621692416529,294509190463488529
%N Least semiprime having prime factors that differ by 2*n!.
%e a(5) = 2761 because 2761 = 11 * 251 , and 251  11 = 240 = 2*120 = 2*5!
%t f[n_] := Block[{p=3}, While[! PrimeQ[p+2*n!], p=NextPrime[p]]; p (p + 2*n!)]; Table[f[n], {n, 60}]
%Y Cf. A190663.
%K nonn
%O 1,1
%A _Michel Lagneau_, May 16 2011
