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 A316785 #43 Feb 11 2021 21:23:57
%S A316785 2,6,6,15,10,21,14,30,18,33,22,455,26,42,30,255,34,133,38,165,42,69,
%T A316785 46,455,50,78,54,435,58,2387,62,255,66,102,70,319865,74,114,78,1353,
%U A316785 82,301,86,345,90,141,94,7735,98,165,102,795,106,399,110,435,114,177,118,1892891
%N A316785 Numerator of an upper bound for the maximal element in phi^(-1)(n).
%C A316785 A057635(n) <= a(n)/A316786(n).
%H A316785 R. Coleman, <a href="https://hal.archives-ouvertes.fr/hal-00718975">Some remarks on Euler's totient function</a>, HAL Id: hal-00718975, version 1, 2012.
%H A316785 H. Gupta, <a href="https://web.archive.org/web/20200728114321/http://www.insa.nic.in/writereaddata/UpLoadedFiles/IJPAM/20005a81_22.pdf">Euler's totient function and its inverse</a>, Indian J. Pure Appl. Math., 12(1) (1981), 22-29.
%F A316785 Numerator of n*Product_{p prime, (p-1)|n} p/(p-1).
%e A316785 For n = 12, there are 5 primes p with (p-1)|12: p1 = 2, p2 = 3, p3 = 5, p4 = 7, and p5 = 13. The numerator of 12*(2/1)*(3/2)*(5/4)*(7/6)*(13/12) = 455/8 is a(12) = 455.
%p A316785 with(numtheory): A316785 := proc(n) local d,N; N:=n; for d in divisors(n) do if is prime(d+1) then N := (N*(d+1))/(d) end if; end do; numer(N); end proc;
%t A316785 a[n_] := Block[{p = Select[Prime@ Range@ PrimePi[n + 1], Mod[n, # - 1] == 0 &]}, Numerator[n*Times @@ (p/(p - 1))]]; Array[a, 60] (* _Robert G. Wilson v_, Aug 01 2018 *)
%o A316785 (PARI) a(n) = my(p=n); fordiv(n, d, if (isprime(d+1), p *= (d+1)/d)); numerator(p); \\ _Michel Marcus_, Jul 29 2018
%Y A316785 Cf. A057635, A316786 (denominators).
%K A316785 nonn,frac
%O A316785 1,1
%A A316785 _Franz Vrabec_, Jul 13 2018