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 A171645 #8 Oct 02 2024 19:21:35 %S A171645 2,4,8,12,18,30,50,70,98,154,242,286,338,442,578,646,722,874,1058, %T A171645 1334,1682,1798,1922,2294,2738 %N A171645 Partial products of Product_{n=1..inf.} (p(n)/p(n-1)*p(n)/p(n-1)), = 2*2*2*(3/2)*(3/2)*(5/3)*(5/3)*(7/5)*(7/5)*(11/7)*(11/7)*...; p = primes, A000040, a(1) = 2. %C A171645 Analogous formulas using A000041 terms = A171646; Fibonacci numbers, A006498; factorials, A010551. %H A171645 Harvey P. Dale, <a href="/A171645/b171645.txt">Table of n, a(n) for n = 1..1000</a> %F A171645 Partial products of Product_{n=1..inf.} (p(n)/p(n-1)*p(n)/p(n-1)), = %F A171645 2*2*2*(3/2)*(3/2)*(5/3)*(5/3)*(7/5)*(7/5)*(11/7)*(11/7)*...; p = primes, %F A171645 A000040, a(1) = 2. %F A171645 a(n)=2*A057602(n-1). [From _R. J. Mathar_, Dec 15 2009] %e A171645 a(10) = 154 = 2*2*2*(3/2)*(3/2)*(5/3)*(5/3)*(7/5)*(7/5)*(11/7). %t A171645 FoldList[Times,Join[{2,2,2},Flatten[{#[[2]]/#[[1]],#[[2]]/#[[1]]}&/@Partition[Prime[Range[20]],2,1]]]] (* _Harvey P. Dale_, Oct 02 2024 *) %Y A171645 Cf. A171646, A006498, A010551. %K A171645 nonn %O A171645 1,1 %A A171645 _Gary W. Adamson_, Dec 13 2009