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 A210508 #43 Feb 18 2025 05:57:01 %S A210508 1,3,36,80662,2598761979625197, %T A210508 2672496879634073073044276636697073994497970453122 %N A210508 a(n) = floor(((Pi^Pi)^Pi)^...^Pi). %C A210508 a(6) has more than 140 decimal digits and is too big to display. - _L. Edson Jeffery_, Jan 28 2013 %F A210508 a(n) = floor(((Pi^Pi)^Pi)^...^Pi) (Pi appears n times). %F A210508 a(n) = floor(Pi^(Pi^(n-1))). - _Charles R Greathouse IV_, Jan 28 2013 %e A210508 Pi^Pi = 36.4621596072079, so a(2) = 36. %p A210508 a:= n-> floor(Pi^(Pi^(n-1))): %p A210508 seq(a(n), n=0..5); # _Alois P. Heinz_, Jul 20 2024 %t A210508 Floor[NestList[#^Pi &, Pi, 5]] (* _Alonso del Arte_, Jan 28 2013 *) %o A210508 (PARI) a(n)=Pi^Pi^n--\1 \\ _Charles R Greathouse IV_, Jan 28 2013 %Y A210508 Cf. A000796, A073236, A096232. %K A210508 nonn %O A210508 0,2 %A A210508 _Jon Perry_, Jan 25 2013 %E A210508 a(4) corrected by _L. Edson Jeffery_ and _Alonso del Arte_, Jan 28 2013 %E A210508 a(5) added by _L. Edson Jeffery_, Jan 28 2013 %E A210508 a(0)=1 prepended by _Alois P. Heinz_, Jul 20 2024