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 A055556 #14 Oct 22 2015 08:09:05 %S A055556 4,72,58800,1757711340,54169994838960,950645196424756293060600, %T A055556 94630125612279498512066506747436400, %U A055556 14119054639791549212725337736060964803166626000 %N A055556 Differences of arithmetic progressions of which the terms give chains of n consecutive nonsquarefree numbers if started with terms of A045882(n) or A051681(n). %H A055556 M. Filaseta and O. Trifonov, <a href="http://dx.doi.org/10.1007/978-1-4612-3464-7_15">On Gaps between Squarefree Numbers</a>. In Analytic Number Theory, Vol 85, 1990, Birkhauser, Basel, pp. 235-253. %H A055556 E. Fogels, <a href="http://dx.doi.org/10.1017/S0305004100017990">On the average values of arithmetic functions</a>, Proc. Cambridge Philos. Soc. 1941, 37: 358-372. %H A055556 K. F. Roth, <a href="http://jlms.oxfordjournals.org/content/s1-26/4/263.extract">On the gaps between squarefree numbers</a>, J. London Math. Soc. 1951 (2) 26:263-268. %F A055556 a(n) = LCM(x, x+1, ..., x+n-1), where x = A045882(n). %e A055556 For n=5, the difference of the relevant progression is 54169994838960. %Y A055556 Cf. A013929, A051681, A045882, A005117, A053797, A005117, A053806. %K A055556 nonn %O A055556 1,1 %A A055556 _Labos Elemer_, Jul 10 2000