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 A066642 #36 Jun 08 2025 15:05:42
%S A066642 1,1,2,5,16,55,216,907,4096,19683,100000,534145,2985984,17403307,
%T A066642 105413504,661735513,4294967296,28761784747,198359290368,
%U A066642 1406563064942,10240000000000,76436817165460,584318301411328,4569515072723572,36520347436056576,298023223876953125
%N A066642 a(n) = floor(n^(n/2)).
%H A066642 Alois P. Heinz, <a href="/A066642/b066642.txt">Table of n, a(n) for n = 0..702</a> (terms n=1..150 from Harry J. Smith)
%e A066642 a(5) = 55 as {5^(1/2)}^5 = 55.9016994374947424102293417182819...
%p A066642 a:= n-> floor(n^(n/2)):
%p A066642 seq(a(n), n=0..25); # _Alois P. Heinz_, Jun 08 2025
%t A066642 Table[ Floor[Sqrt[n]^n], {n, 1, 25} ]
%o A066642 (PARI) a(n) = sqrtint(n^n); \\ _Michel Marcus_, Nov 01 2022
%o A066642 (Magma) [Floor(n^(n/2)): n in [1..25]]; // _G. C. Greubel_, Dec 30 2017
%o A066642 (Python)
%o A066642 from math import isqrt
%o A066642 def A066642(n): return isqrt(n**n) # _Chai Wah Wu_, Jun 08 2025
%Y A066642 Cf. A092503, A147771, A190343.
%Y A066642 Bisection gives A062971 (even part).
%K A066642 easy,nonn
%O A066642 0,3
%A A066642 _Amarnath Murthy_, Dec 29 2001
%E A066642 More terms from _Robert G. Wilson v_, Jan 03 2002
%E A066642 a(0)=1 prepended by _Alois P. Heinz_, Jun 08 2025