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 A006448 M5029 #29 Dec 19 2021 12:01:42
%S A006448 1,16,9882,715860992,12417636281312500,85953540009068492207916672,
%T A006448 356838302112667713247240882121025536249,
%U A006448 1245456693529103515171728481423145699858332531028201472
%N A006448 Number of n-element algebras with 1 binary operator and 1 constant (pointed groupoids).
%D A006448 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A006448 M. A. Harrison, <a href="https://doi.org/10.1090/S0002-9939-1966-0200219-9">The number of isomorphism types of finite algebras</a>, Proc. Amer. Math. Soc., 17 (1966), 731-737.
%H A006448 <a href="/index/Gre#groupoids">Index entries for sequences related to groupoids</a>
%F A006448 For a list n(1), n(2), n(3), ..., let fixF[n] = n(1)*Product_{i, j >= 1} (Sum_{d|[ i, j ]} (d*n(d))^((i, j)*n(i)*n(j))), where [i,j] = lcm(i,j). [Note that the notation fixF[n] appears in several other formulas contributed by _Christian G. Bower_. In this case it seems that the prefix "fix" was accidentally removed over the course of the years. - _N. J. A. Sloane_, Dec 19 2021]
%F A006448 a(n) = Sum_{1*s_1+2*s_2+...=n} (fixA[s_1, s_2, ...]/(1^s_1*s_1!*2^s_2*s2!*...)) where fixA[s_1, s_2, ...] = s_1 * Product_{i, j>=1} ( (Sum_{d|lcm(i, j)} (d*s_d))^(gcd(i, j)*s_i*s_j)).
%F A006448 a(n) is asymptotic to n^(n^2+1)/n!.
%Y A006448 Cf. A001329.
%K A006448 nonn,easy,nice
%O A006448 1,2
%A A006448 _N. J. A. Sloane_
%E A006448 Formula and more terms from _Christian G. Bower_, May 08 1998, Dec 03 2003