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 A090531 #13 Jan 27 2020 13:40:40
%S A090531 4,4,6,72,240,12240,35280,241920,1088640,50803200,1157587200,
%T A090531 14370048000,298896998400,2353813862400,11769069312000,
%U A090531 502146957312000,4268249137152000,621030249455616000,9488317831888896000
%N A090531 Least multiple of n! sandwiched between twin primes, or 0 if no such number exists.
%C A090531 Conjecture: No term is zero.
%C A090531 This conjecture is implied by Dickson's conjecture. - _Robert Israel_, Feb 13 2018
%H A090531 Robert Israel, <a href="/A090531/b090531.txt">Table of n, a(n) for n = 1..447</a>
%F A090531 a(n) = A071256(A000142(n)). - _Robert Israel_, Feb 13 2018
%p A090531 f := proc (n) local k, t; t := factorial(n); for k from t by t do if isprime(k-1) and isprime(k+1) then return k end if end do end proc;
%p A090531 map(f, [`$`(1 .. 20)]); # _Robert Israel_, Feb 13 2018
%t A090531 lmn[n_]:=Module[{k=n!,m=1},While[AnyTrue[k*m+{1,-1},CompositeQ],m++];k*m]; Join[{4,4},Array[lmn,20,3]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jan 27 2020 *)
%Y A090531 Cf. A000142, A071256, A090530.
%K A090531 nonn
%O A090531 1,1
%A A090531 _Amarnath Murthy_, Dec 07 2003
%E A090531 More terms from _Ryan Propper_, Jun 16 2005