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 A143931 #12 Feb 17 2023 14:47:56
%S A143931 2,2,3,11,19,31,79,209,607,1921,6337,21907,78913,295289,1143539,
%T A143931 4574149,18859733,80014841,348776611,1559776279,7147792823,
%U A143931 33526120127,160785623627,787685471389,3938427356623,20082117944263,104349745809077
%N A143931 a(n) is the smallest positive integer x such that x^2 - n! is prime.
%C A143931 For the smallest positive prime numbers of the form x^2 - n! see A143932.
%C A143931 For primes x in this sequence see A143933.
%e A143931 a(1)=2 because 2^2-1! = 3 is prime;
%e A143931 a(2)=2 because 2^2-2! = 2 is prime;
%e A143931 a(3)=3 because 3^2-3! = 3 is prime;
%e A143931 a(4)=11 because 11^2-4! = 97 is prime.
%t A143931 a = {}; Do[k = Round[Sqrt[n! ]] + 1; While[ ! PrimeQ[k^2 - n! ], k++ ]; AppendTo[a, k], {n, 1, 50}]; a
%t A143931 spi[n_]:=Module[{k=Ceiling[Sqrt[n!]],nf=n!},While[!PrimeQ[k^2-nf],k++];k]; Array[ spi,30] (* _Harvey P. Dale_, Feb 17 2023 *)
%Y A143931 Cf. A121926, A143932, A143933.
%K A143931 nonn
%O A143931 1,1
%A A143931 _Artur Jasinski_, Sep 05 2008