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 A137321 #15 Aug 11 2023 11:55:01
%S A137321 2,3,2405,460663,198133379411,281952316704253,776149319714627324177,
%T A137321 1357971253927074149763979,12038706006108210079811416910567,
%U A137321 2195692826371309917093828766580180926483469,16546151513256634846850635804959240464844734431,5052512795965694464228024657195578053165744330410199442517
%N A137321 a(n) = prime(n)^prime(n) - k!, where prime(n) is the n-th prime number, and k is the greatest number for which k! <= prime(n)^prime(n).
%e A137321 a(3) = prime(3)^prime(3) - 6! = 5^5 - 720 = 3125 - 720 = 2405.
%t A137321 With[{f=Range[60]!},Table[p^p-Max[Select[f,#<p^p&]],{p,Prime[Range[15]]}]] (* _Harvey P. Dale_, Aug 11 2023 *)
%o A137321 (PARI) a(n) = my(k=1, P=prime(n)^prime(n)); until (k! > P, k++); P - (k-1)!; \\ _Michel Marcus_, Mar 15 2022
%Y A137321 Cf. A136437, A000040, A000142.
%K A137321 easy,nonn
%O A137321 1,1
%A A137321 _Ctibor O. Zizka_, Apr 06 2008
%E A137321 Name corrected and more terms from _Michel Marcus_, Mar 15 2022