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 A208450 #16 Feb 20 2025 16:36:36 %S A208450 1,2,3,4,5,6,21,16,9,10,55,12,39,112,315,16,170,18,513,80,105,22,8855, %T A208450 96,75,416,3159,28,203,30,9765,640,132,816,32725,36,333,304,140049,40, %U A208450 13325,42,13545,39424,495,46,2080925,288,5292,1600,11475,52,117130 %N A208450 Denominator of A010786(n+1) / A010786(n). %H A208450 Reinhard Zumkeller, <a href="/A208450/b208450.txt">Table of n, a(n) for n = 1..1000</a> %F A208450 a(n) = A010786(n) / A208448(n). %F A208450 a(n) = A377484(n+1)/gcd(A007955(n+1), A377484(n+1)). - _Ridouane Oudra_, Feb 08 2025 %t A208450 A208450[n_] := Times @@ (# - 1) / GCD[Times @@ #, Times @@ (# - 1)] & [Rest[Divisors[n + 1]]]; %t A208450 Array[A208450, 100] (* _Paolo Xausa_, Feb 20 2025 *) %o A208450 (Haskell) %o A208450 import Data.Ratio ((%), denominator) %o A208450 a208450 n = a208450_list !! (n-1) %o A208450 a208450_list = map denominator $ %o A208450 zipWith (%) (tail a010786_list) a010786_list %Y A208450 Cf. A208449 (numerator). %Y A208450 Cf. A007955, A377484. %K A208450 nonn,frac %O A208450 1,2 %A A208450 _Reinhard Zumkeller_, Feb 26 2012