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 A328403 #11 Oct 18 2019 11:29:13
%S A328403 3,6,5,18,7,43218,125,1050,16807,10,161051,1320550,7105308412125,
%T A328403 7357350,265837,835182761270,2292646180979,146410,
%U A328403 258413198822535882125,107718961350,1045726245479028578048875581177070937,32310040537956402036523898190,528950766088569054716797662440479
%N A328403 a(n) = A276086(A276086(A276086(n))), where A276086(n) converts primorial base expansion of n into its prime product form.
%H A328403 Antti Karttunen, <a href="/A328403/b328403.txt">Table of n, a(n) for n = 0..134</a>
%H A328403 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%F A328403 a(n) = A276086(A276087(n)) = A276086(A276086(A276086(n))).
%F A328403 A051903(a(n)) = A328394(n).
%F A328403 A061395(a(n)) = A328405(n).
%F A328403 A328114(a(n)) = A328398(n).
%F A328403 A235224(a(n)) = A328406(n).
%t A328403 Block[{b = MixedRadix[Reverse@ Prime@ Range@ 120], f}, f[n_] := Times @@ Power @@@ # &@ Transpose@ {Prime@ Range@ Length@ #, Reverse@ #} &@ IntegerDigits[n, b]; Array[Nest[f, #, 3] &, 23, 0]] (* _Michael De Vlieger_, Oct 17 2019 *)
%o A328403 (PARI)
%o A328403 A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
%o A328403 A328403(n) = A276086(A276086(A276086(n)));
%Y A328403 Cf. A276086, A276087, A328316, A328394, A328398, A328405, A328406.
%K A328403 nonn
%O A328403 0,1
%A A328403 _Antti Karttunen_, Oct 15 2019