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%I #8 Mar 30 2012 17:22:34
%S 1,2,6,24,48,120,240,720
%N Numbers n such that the equation S(k) = S(n+k) has no solutions for k <= n, where S is the Kempner function A002034.
%C No other n < 10^6. Note that n is a factorial or twice a factorial. For n = 1 and 6, there is no known k such that S(k) = S(n+k). For n = 2, 24, 48, 120, 240 and 720, the least k is respectively 16, 48, 10192, 240, 3600 and 3888.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/SmarandacheFunction.html">Smarandache Function</a>
%t (*See A002034 for the Kempner function*) a=Table[Kempner[i], {i, 2000}]; lst={}; Do[i=1; While[i<=n&&a[[i]] != a[[i+n]], i++ ]; If[i>n, AppendTo[lst, n]], {n, 1000}]; lst
%Y Cf. A099143 (least k such that S(k) = S(k+n)).
%K nonn
%O 1,2
%A _T. D. Noe_, Sep 30 2004
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