cp's OEIS Frontend

A387027 a(n) = lcm({1, 2, ..., n}) * (n + 1) / n for n > 0, a(0) = 1.

%I A387027 #18 Aug 19 2025 04:15:27
%S A387027 1,2,3,8,15,72,70,480,945,2800,2772,30240,30030,388080,386100,384384,
%T A387027 765765,12972960,12932920,245044800,244432188,243877920,243374040,
%U A387027 5587021440,5577321750,27841990176,27800803800,83288004800,83181770100,2409402996000,2406725881560
%N A387027 a(n) = lcm({1, 2, ..., n}) * (n + 1) / n for n > 0, a(0) = 1.
%H A387027 Paolo Xausa, <a href="/A387027/b387027.txt">Table of n, a(n) for n = 0..2000</a>
%F A387027 a(n) = A003418(n) * (n + 1) / n for n >= 1.
%F A387027 a(n) = (n+1)*A002944(n). - _R. J. Mathar_, Aug 19 2025
%p A387027 A387027 := n -> local k; ifelse(n = 0, 1, ((n+1) * lcm(seq(k, k = 1..n))) / n):
%p A387027 seq(A387027(n), n = 0..30);
%t A387027 A387027[n_] := If[n == 0, 1, Quotient[(n + 1) LCM @@ Range[1, n], n]];
%t A387027 Table[A387027[n], {n, 0, 30}]
%o A387027 (Python)
%o A387027 from math import lcm
%o A387027 def A387027(n): return (n+1)*lcm(*range(1,n+1))//n if n else 1 # _Chai Wah Wu_, Aug 17 2025
%Y A387027 Cf. A003418.
%K A387027 nonn
%O A387027 0,2
%A A387027 _Peter Luschny_, Aug 17 2025