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 A147998 #12 Aug 19 2024 12:53:15
%S A147998 1,3,12,72,576,5184,57024,684288,9580032,153280512,2605768704,
%T A147998 49509605376,1039701712896,22873437683712,548962504409088,
%U A147998 13724062610227200,370549690476134400,10745941023807897600,322378230714236928000,10316103382855581696000,340431411634234195968000,11915099407198196858880000,440858678066333283778560000,16752629766520664783585280000,670105190660826591343411200000
%N A147998 [r]*[2r]*[3r]*...[nr], where r=(1+sqrt(5))/2 and []=floor.
%F A147998 a(n)=[r]*[2r]*[3r]*...[nr], where r=(1+sqrt(5))/2 and []=floor.
%F A147998 a(n) ~ c * r^n * n! / n^(1/(2*r)), where c = 0.7044932... and r = A001622 is the golden ratio. - _Vaclav Kotesovec_, Aug 19 2024
%e A147998 a(n)=1*3*12*72*...*floor(r*n), where r = golden ratio.
%t A147998 a[n_]:=Floor[n*(1+5^(1/2))/2];
%t A147998 f[n_]:=Product[a[i],{i,n}];
%t A147998 Table[f[n],{n,1,25}]
%Y A147998 Cf. A000201 (lower Wythoff sequence).
%K A147998 nonn
%O A147998 1,2
%A A147998 _Clark Kimberling_, Jan 22 2011