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 A243757 #27 Sep 04 2021 03:54:37
%S A243757 1,1,1,1,1,5,5,5,5,5,25,25,25,25,25,125,125,125,125,125,625,625,625,
%T A243757 625,625,15625,15625,15625,15625,15625,78125,78125,78125,78125,78125,
%U A243757 390625,390625,390625,390625,390625,1953125,1953125,1953125,1953125,1953125,9765625
%N A243757 a(n) = Product_{i=1..n} A060904(i).
%C A243757 This is the generalized factorial for A060904.
%C A243757 a(0) = 1 as it represents the empty product.
%C A243757 a(n) is the largest power of 5 that divides n!, or the order of a 5-Sylow subgroup of the symmetric group of degree n. - _David Radcliffe_, Sep 03 2021
%H A243757 Reinhard Zumkeller, <a href="/A243757/b243757.txt">Table of n, a(n) for n = 0..1000</a>
%H A243757 Tyler Ball, Tom Edgar, and Daniel Juda, <a href="http://dx.doi.org/10.4169/math.mag.87.2.135">Dominance Orders, Generalized Binomial Coefficients, and Kummer's Theorem</a>, Mathematics Magazine, Vol. 87, No. 2, April 2014, pp. 135-143.
%F A243757 a(n) = Product_{i=1..n} A060904(i).
%F A243757 a(n) = 5^(A027868(n)).
%t A243757 Table[Product[5^IntegerExponent[k, 5], {k, 1, n}], {n, 0, 20}] (* _G. C. Greubel_, Dec 24 2016 *)
%o A243757 (Sage)
%o A243757 S=[0]+[5^valuation(i, 5) for i in [1..100]]
%o A243757 [prod(S[1:i+1]) for i in [0..99]]
%o A243757 (Haskell)
%o A243757 a243757 n = a243757_list !! n
%o A243757 a243757_list = scanl (*) 1 a060904_list
%o A243757 -- _Reinhard Zumkeller_, Feb 04 2015
%o A243757 (PARI) a(n) = prod(k=1,n, 5^valuation(k,5)); \\ _G. C. Greubel_, Dec 24 2016
%Y A243757 Cf. A027868, A060818, A060828, A060904, A242954.
%K A243757 nonn
%O A243757 0,6
%A A243757 _Tom Edgar_, Jun 10 2014