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 A254380 #24 Apr 03 2023 10:36:13 %S A254380 2,3,19,11251 %N A254380 2^2*3^3*...*a(n)^a(n) + 1 is prime, a(n) is prime, a(n)>a(n-1), and a(n) is minimal. %C A254380 Observation: a(2)..a(4) coincide with a(1)..a(3) from A191623. - _Omar E. Pol_, Jan 30 2015 %H A254380 Chris K. Caldwell and G. L. Honaker, Jr. <a href="https://t5k.org/curios/page.php?curio_id=27483">Prime Curios!</a> %e A254380 a(1)=2 because 2 and (2^2)+1=5 are prime. %e A254380 a(2)=3 because 3 and (2^2*3^3)+1=109 are prime. %e A254380 a(3)=19 because 19 and (2^2*3^3*19^19)+1=213669322811313867625389733 are prime, and this did not work for either 5, 7, 11, 13. %Y A254380 Cf. A000040, A051674, A191623. %K A254380 nonn,hard,more %O A254380 1,1 %A A254380 _G. L. Honaker, Jr._, Jan 29 2015 %E A254380 a(4) found by _Chris K. Caldwell_