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 A358972 #30 Dec 09 2022 06:17:14 %S A358972 1,2,36,36520347436056576 %N A358972 a(n) = ((...((n!^(n-1)!)^(n-2)!)^...)^2!)^1!. %C A358972 Like n!^(n-1!)^...^2!^1! (A073581), but with all power operators nested from the left. %C A358972 This sequence grows roughly doubly-exponentially. - _Charles R Greathouse IV_, Dec 07 2022 %H A358972 Arsen Vardanyan, <a href="/A358972/b358972.txt">Table of n, a(n) for n = 1..5</a> %F A358972 a(n) = n!^A000178(n-1). - _Charles R Greathouse IV_, Dec 07 2022 %F A358972 log log a(n) ~ 0.5*n^2*log^2 n. - _Charles R Greathouse IV_, Dec 07 2022 %e A358972 a(4) = ((4!^3!)^2!)^1! = (24^6)^2 = 191102976^2 = 36520347436056576 %o A358972 (PARI) a(n) = n!^prod(i=2,n-1,i^(n-i)); \\ _Kevin Ryde_, Dec 09 2022 %Y A358972 Cf. A000178, A067039. %Y A358972 Cf. A073581 (exponents right to left). %K A358972 nonn %O A358972 1,2 %A A358972 _Arsen Vardanyan_, Dec 07 2022