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 A118912 #7 Feb 18 2025 15:44:58 %S A118912 2,13,28559,665230244078823349, %T A118912 195833931687186822327230545227550596864953022841534058316595001440791433 %N A118912 a(1) = 2; a(n) is greatest prime < a(n-1)^4. %C A118912 Exponent-4 analog of A059785 a(n+1)=prevprime(a(n)^2), with exponent 3 being A118910 a(1) = 2; a(n) is greatest prime < a(n-1)^3. %F A118912 a(1) = 2; a(n) is greatest prime < a(n-1)^4. %e A118912 a(1) = 2, by definition. %e A118912 a(2) = 13 = 2^4 - 3. %e A118912 a(3) = 28559 = 13^4 - 2. %e A118912 a(4) = 665230244078823349 = 28559^4 - 12. %e A118912 a(5) = 195833931687186822327230545227550596864953022841534058316595001440791433 = 665230244078823349^4 - 168. %e A118912 a(6) is too large to include. %t A118912 NestList[NextPrime[#^4,-1]&,2,5] (* _Harvey P. Dale_, Feb 18 2025 *) %Y A118912 Cf. A001358, A055496, A076656, A006992, A005384, A005385, A118908-A118913. %K A118912 easy,nonn %O A118912 1,1 %A A118912 _Jonathan Vos Post_, May 05 2006