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 A348261 #27 Oct 14 2021 12:47:10
%S A348261 2,3,8,2,1,7,9,0,8,7,9,9,3,0,1,8,7,7,4,5,5,5,5,9,3,0,5,2,5,2,0,8,7,8,
%T A348261 5,3,5,6,8,9,7,6,7,9,9,6,7,8,2,3,2,5,9,1,0,1,2,9,4,8,1,1,7,7,1,3,5,3,
%U A348261 4,4,4,6,9,0,7,4,6,9,3,5,4,1,6,6,8,7,5,8,2,5,3,9,6,1,6,6,9,2,2,0,8,9,7,2,1,4
%N A348261 Decimal expansion of the nontrivial number x for which x^Pi = Pi^x.
%C A348261 The x-th root of x equals the Pi-th root of Pi: x^(1/x) = Pi^(1/Pi) = A073238 = 1.43961949584759... .
%C A348261 Like Pi, is x also transcendental?
%F A348261 Equals -Pi*LambertW(-log(Pi)/Pi)/log(Pi). - _Alois P. Heinz_, Oct 13 2021
%e A348261 2.382179087993018774555593052520878...
%e A348261 x^Pi = Pi^x = 15.28621734783496640312486439999472... .
%p A348261 evalf((t-> -LambertW(-t)/t)(log(Pi)/Pi), 120); # _Alois P. Heinz_, Oct 13 2021
%t A348261 {a, b} = NSolve[x^Pi == Pi^x, x, WorkingPrecision -> 300]; a; RealDigits[N[x/.a, 300]][[1]]
%Y A348261 Cf. A000796 (Pi), A049541 (1/Pi), A073238 (Pi^(1/Pi)), A073226 (e^e, see first comment), A231737.
%K A348261 nonn,cons
%O A348261 1,1
%A A348261 _Timothy L. Tiffin_, Oct 08 2021