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 A319949 #24 Mar 21 2024 11:41:43
%S A319949 1,2,8,40,240,1920,17280,172800,2073600,26956800,377395200,6038323200,
%T A319949 102651494400,1847726899200,36954537984000,776045297664000,
%U A319949 17072996548608000,409751917166592000,10243797929164800000,266338746158284800000
%N A319949 a(n) = Product_{i=1..n} floor(4*i/3).
%H A319949 Harvey P. Dale, <a href="/A319949/b319949.txt">Table of n, a(n) for n = 1..429</a>
%F A319949 a(n) ~ (4/3)^n * n! * 2*sqrt(Pi) / (3^(1/4) * Gamma(1/4) * n^(1/4)).
%F A319949 Recurrence: 27*(3*n - 7)*a(n) = 54*(2*n - 5)*a(n-1) + 12*(12*n^2 - 42*n + 35)*a(n-2) + 8*(n-2)*(2*n - 5)*(3*n - 4)*(4*n - 9)*a(n-3).
%t A319949 Table[Product[Floor[i*4/3], {i, 1, n}], {n, 1, 20}]
%t A319949 RecurrenceTable[{27*(3*n - 7)*a[n] == 54*(2*n - 5)*a[n-1] + 12*(12*n^2 - 42*n + 35)*a[n-2] + 8*(n-2)*(2*n - 5)*(3*n - 4)*(4*n - 9)*a[n-3], a[1]==1, a[2]==2, a[3]==8}, a, {n, 1, 20}]
%t A319949 FoldList[Times,Floor[4 Range[20]/3]] (* _Harvey P. Dale_, Mar 21 2024 *)
%o A319949 (PARI) a(n) = prod(i=1, n, (4*i)\3); \\ _Michel Marcus_, Oct 03 2018
%Y A319949 Cf. A004773, A010786, A180736, A275062, A319948, A319950.
%K A319949 nonn
%O A319949 1,2
%A A319949 _Vaclav Kotesovec_, Oct 02 2018