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 A058251 #22 Aug 16 2024 21:12:39 %S A058251 1,2,6,120,1680,36960,5765760,1568286720,536354058240,24672286679040, %T A058251 2861985254768640,2661646286934835200,3545312854197200486400, %U A058251 5814313080883408797696000,10500649424075436288638976000 %N A058251 LCM of n-th primorial number and its Euler totient. %F A058251 a(n) = LCM(A002110(n), A000010(A002110(n))) = LCM(A002110(n), A005867(n)). %F A058251 a(n) = A009262(A002110(n)). - _Michel Marcus_, Apr 27 2022 %e A058251 a(6) = LCM(30030,5760) = 5765760. %p A058251 [seq(ilcm(product(ithprime(k), k=1..m), product(ithprime(k)-1, k=1..m)), m=1..20)]; %t A058251 LCM[#,EulerPhi[#]]&/@Rest[FoldList[Times,1,Prime[Range[15]]]] (* _Harvey P. Dale_, Nov 29 2011 *) %o A058251 (PARI) P(n) = prod(k=1, n, prime(k)); \\ A002110 %o A058251 a(n) = my(p= P(n)); lcm(p, eulerphi(p)); \\ _Michel Marcus_, Apr 27 2022 %Y A058251 Cf. A002110, A000010, A005867, A009262. %K A058251 nonn %O A058251 0,2 %A A058251 _Labos Elemer_, Dec 05 2000 %E A058251 a(0)=1 inserted by _Jamie Morken_, Apr 27 2022