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 A002584 M3952 N1628 #55 Feb 13 2020 11:57:10 %S A002584 1,5,29,19,2309,30029,8369,929,46027,81894851,876817,38669, %T A002584 304250263527209,92608862041,59799107,1143707681,69664915493, %U A002584 1146665184811,17975352936245519,2140320249725509 %N A002584 Largest prime factor of product of first n primes - 1, or 1 if no such prime exists. %C A002584 The products of the first primes are called primorial numbers. - _Franklin T. Adams-Watters_, Jun 12 2014 %D A002584 M. Kraitchik, On the divisibility of factorials, Scripta Math., 14 (1948), 24-26 (but beware errors). %D A002584 M. Kraitchik, Introduction à la Théorie des Nombres. Gauthier-Villars, Paris, 1952, p. 2. %D A002584 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A002584 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A002584 Sean A. Irvine and Amiram Eldar, <a href="/A002584/b002584.txt">Table of n, a(n) for n = 1..99</a> (terms 1..91 from Sean A. Irvine) %H A002584 A. Borning, <a href="http://dx.doi.org/10.1090/S0025-5718-1972-0308018-5 ">Some results for k!+-1 and 2.3.5...p+-1</a>, Math. Comp., 26 (1972), 567-570. %H A002584 M. Kraitchik, <a href="/A002582/a002582.pdf">On the divisibility of factorials</a>, Scripta Math., 14 (1948), 24-26 (but beware errors). [Annotated scanned copy] %H A002584 S. Kravitz and D. E. Penney, <a href="http://www.jstor.org/stable/2689826">An extension of Trigg's table</a>, Math. Mag., 48 (1975), 92-96. %H A002584 S. Kravitz and D. E. Penney, <a href="/A002584/a002584.pdf">An extension of Trigg's table</a>, Math. Mag., 48 (1975), 92-96. [Annotated scanned copy; also letter from N. J. A. Sloane to John Selfridge] %H A002584 Hisanori Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/matha103.htm">Factorizations of many number sequences</a> %H A002584 John Selfridge, Marvin Wunderlich, Robert Morris, N. J. A. Sloane, <a href="/A002584/a002584_1.pdf">Correspondence, 1975</a> %H A002584 R. G. Wilson v, <a href="/A038507/a038507.txt">Explicit factorizations</a>. %F A002584 a(n) = A006530(A057588(n)). - _Amiram Eldar_, Feb 13 2020 %t A002584 Prepend[Table[ Max[Transpose[FactorInteger[(Times @@ Prime[Range[i]]) - 1]][[1]]], {i, 2, 20}], 1] %t A002584 FactorInteger[#][[-1,1]]&/@Rest[FoldList[Times,1,Prime[Range[20]]]-1] (* _Harvey P. Dale_, Feb 27 2013 *) %o A002584 (PARI) a(n)=if(n>1, my(f=factor(prod(i=1,f,prime(i)))[,1]); f[#f], 1) \\ _Charles R Greathouse IV_, Feb 08 2017 %Y A002584 Cf. A002110, A002585, A006530, A057588. %K A002584 nonn,nice %O A002584 1,2 %A A002584 _N. J. A. Sloane_ %E A002584 More terms from J. L. Selfridge %E A002584 Further terms from _Labos Elemer_, Oct 25 2000