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 A358990 #8 Dec 11 2022 12:01:02
%S A358990 1,1,3,21,189,2079,27027,459459,8729721,183324141,4216455243,
%T A358990 113844291561,3301484455269,102346018113339,3377418597740187,
%U A358990 124964488116386919,4873615036539089841,199818216498102683481,8592183309418415389683,403832615542665523315101,19787798161590610642439949
%N A358990 a(n) is the product of the first n odd numbers not divisible by 5.
%C A358990 Unlike the factorial number n!, but like A356858(n), a(n) does not have trailing zeros.
%F A358990 a(n) = Product_{k=1..n} A045572(k).
%t A358990 Table[Product[2*k+2*Floor[(k-3)/4]+1,{k,n}],{n,0,20}]
%o A358990 (PARI) f(n) = 2*n - 1 + (n+1)\4 * 2; \\ A045572
%o A358990 a(n) = prod(k=1, n, f(k)); \\ _Michel Marcus_, Dec 10 2022
%Y A358990 Cf. A000142, A045572, A356858.
%Y A358990 Cf. A358991 (number of zero digits), A358992 (number of digits), A358993 (number of nonzero digits).
%K A358990 nonn
%O A358990 0,3
%A A358990 _Stefano Spezia_, Dec 09 2022