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 A336743 #32 Oct 19 2020 00:41:34
%S A336743 1,3,15,90,810,8100,97200,1458000,24786000,446148000,8922960000,
%T A336743 205228080000,4925473920000,132987795840000,3856646079360000,
%U A336743 115699382380800000,3818079618566400000,129814707031257600000,4673329453125273600000,182259848671885670400000
%N A336743 a(n) is the product of the first n positive evil numbers.
%C A336743 Despite 0 appearing in the evil numbers, it is excluded here for obvious reasons.
%C A336743 This sequence features a mixture of odious and evil numbers, demonstrated in terms such as a(5) and a(8), where 8100 is evil but 24768000 is odious. As such, this shows that despite doubling preserving evilness, this is untrue for all multipliers.
%F A336743 a(n) = Product_{k=2, n+1} A001969(k). - _Michel Marcus_, Sep 27 2020
%e A336743 a(3) = 3*5*6 = 90.
%e A336743 a(8) = 3*5*6*9*10*12*15*17 = 24786000.
%t A336743 FoldList[Times, 1, Select[Range[40], EvenQ @ DigitCount[#, 2, 1] &]] (* _Amiram Eldar_, Sep 26 2020 *)
%Y A336743 Cf. A000142, A000069 (odious), A001969 (evil).
%K A336743 nonn,base
%O A336743 0,2
%A A336743 _Jamie Robert Creasey_, Sep 26 2020