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 A108518 #11 May 21 2024 05:29:15
%S A108518 1,11,229,1283,44159
%N A108518 a(n) is the smallest natural number m such that (10^n)! + m is prime.
%C A108518 If a(n) is composite then a(n)>10^(2n)+2*10^n. Conjecture: All terms are noncomposite numbers.
%C A108518 (10^4)!+44159 is a probable prime. - _Jason Yuen_, May 20 2024
%F A108518 a(n) = A033932(10^n). - _Jason Yuen_, May 20 2024
%e A108518 a(3)=1283 because (10^3)!+1283 is prime and for 0<m<1283 1000!+m is
%e A108518 composite.
%t A108518 a[n_] := (For[m = 1, ! PrimeQ[(10^n)! + m], m++ ]; m); Do[Print[a[n]], {n, 0, 3}]
%t A108518 sp[n_]:=Module[{c=(10^n)!},NextPrime[c]-c]; Array[sp,4,0] (* _Harvey P. Dale_, Jul 29 2013 *)
%Y A108518 Cf. A108519, A033932.
%K A108518 more,nonn,hard
%O A108518 0,2
%A A108518 _Farideh Firoozbakht_, Jul 10 2005
%E A108518 a(4) from _Jason Yuen_, May 20 2024