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 A383471 #17 Jul 23 2025 16:07:58
%S A383471 1,2,3,6,12,23,46,93,185,370,739,1478,2955,5910,11819,23637,47274,
%T A383471 94549,189097,378194,756388,1512776,3025551,6051102,12102203,24204407,
%U A383471 48408813,96817626,193635251,387270501,774541003,1549082005,3098164010,6196328019,12392656038,24785312075
%N A383471 a(n) = round(Product_{k=1..n} (1 + 1/2^2^(-k))).
%t A383471 Floor[Product[(1+2^(-2^(-k))),{k,1,n}]+1/2]
%o A383471 (PARI) a(n) = round(prod(k=1, n, 1 + 1/2^2^(-k))); \\ _Michel Marcus_, Apr 28 2025
%Y A383471 Cf. A014571, A215016.
%K A383471 nonn
%O A383471 0,2
%A A383471 _Greg Huber_, Apr 27 2025