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 A375921 #29 Sep 27 2024 03:54:04 %S A375921 1,10,70,420,4620,60060,60060,2042040,38798760,38798760,892371480, %T A375921 4461857400,13385572200,388181593800,12033629407800,24067258815600, %U A375921 24067258815600,890488576177200,890488576177200,36510031623265200,1569931359800403600,1569931359800403600 %N A375921 a(n) = LCM(1,2, ..., 2n+1)/6. %C A375921 Agrees largely with A101029. The first difference is at n=8 for which a(8)/A101029(8) = 5. There are also other differences; the ratio of the two series entries appears to be always an integer. %H A375921 Gregory Gerard Wojnar, <a href="/A375921/b375921.txt">Table of n, a(n) for n = 1..50</a> %F A375921 a(n) = A003418(2n+1)/6. %t A375921 a[n_]:= LCM@@Range[1,2n+1]/6; Array[a,22] (* _Stefano Spezia_, Sep 02 2024 *) %o A375921 (PARI) a(n) = lcm([1..2*n+1])/6; \\ _Michel Marcus_, Sep 02 2024 %o A375921 (Python) %o A375921 from math import lcm %o A375921 def A375921(n): return lcm(*range(1,n+1<<1))//6 # _Chai Wah Wu_, Sep 26 2024 %Y A375921 Cf. A003418, A101029. %K A375921 nonn %O A375921 1,2 %A A375921 _Gregory Gerard Wojnar_, Sep 02 2024