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 A109289 #10 Oct 13 2019 09:45:54
%S A109289 4,6,8,9,10,12,14,18,20,21,24,25,26,28,30,32,33,38,42,44,45,46,48,49,
%T A109289 50,51,54,55,57,60,62,64,65,68,69,72,74,76,77,80,81,82,84,85,90,91,93,
%U A109289 98,99,100,102,104,105,106,108,110,111,114,115,117,118,121,122,125,126,128
%N A109289 Composite numbers which are not of the form p*q + 1, where p and q are distinct primes.
%t A109289 Select[Range[2, 130], ! (PrimeQ[ # ] || (Plus @@ Last /@ FactorInteger[ # - 1] == 2 && Length[FactorInteger[ # - 1]] == 2)) &] (* _Ray Chandler_, Aug 25 2005 *)
%t A109289 fQ[n_] := Last /@ FactorInteger[n] != {1, 1}; Select[ Range[2, 128], !PrimeQ[ # ] && fQ[ # - 1] &] (* _Robert G. Wilson v_ *)
%Y A109289 Cf. A109287, A109288, A109290.
%K A109289 easy,nonn
%O A109289 1,1
%A A109289 _Giovanni Teofilatto_, Aug 20 2005
%E A109289 Extended by _Robert G. Wilson v_ and _Ray Chandler_, Aug 25 2005