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 A173614 #22 Jan 05 2025 19:51:39
%S A173614 1,2,1,4,2,6,1,2,4,10,2,12,6,4,1,16,2,18,4,6,10,22,2,4,12,2,6,28,4,30,
%T A173614 1,10,16,12,2,36,18,12,4,40,6,42,10,4,22,46,2,6,4,16,12,52,2,20,6,18,
%U A173614 28,58,4,60,30,6,1,12,10,66,16,22,12,70,2,72,36,4,18,30,12,78,4,2,40,82,6
%N A173614 a(n) = lcm_{p is prime and divisor of n} p-1.
%C A173614 The function psi(n) in the paper by Carlip et al. - _R. J. Mathar_, Aug 22 2012
%H A173614 Andrew Howroyd, <a href="/A173614/b173614.txt">Table of n, a(n) for n = 2..10000</a>
%H A173614 W. Carlip, E. Jacobson, and L. Somer, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/36-4.html">Pseudoprimes, perfect numbers and a problem of Lehmer</a>, Fib. Quart. 36 (4) (1998) 361
%F A173614 Conjecture: a(n) = A002322(A007947(n)). - _Velin Yanev_, Feb 06 2021
%e A173614 1425 = 3*5^2*19 => a(1425) = lcm(2,4,18) = 36.
%t A173614 a[n_] := {aux = 1; fa = FactorInteger[n]; len = Length[fa]; grau = Table[fa[[s]][[1]] - 1, {s, len}]; Do[aux = LCM[aux, grau[[i]]], {i, len}]; aux}[[1]]; Table[a[n], {n, 2, 40}]
%o A173614 (PARI) a(n)=lcm(apply(p->p-1, factor(n)[,1])) \\ _Andrew Howroyd_, Aug 06 2018
%K A173614 nonn
%O A173614 2,2
%A A173614 _José María Grau Ribas_, Feb 22 2010