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%I #16 Oct 15 2013 22:30:50
%S 434,104,80,182,427,1727,4147,7163,42031,165841,569257,2683909,
%T 10040081,39094849,155533969,717519401,3041377519,16076525809,
%U 71749935913
%N a(n) = least composite number such that sigma(a(n)+n!) = sigma(a(n))+n! where sigma() = A000203.
%C a(21) <= 328823468719, a(22) <= 1542201899569, a(23) <= 9325753929619. - _Donovan Johnson_, Sep 22 2013
%e a(7) = 1727 = 11*157, 4 divisors, sigma(1727)+5040 = 1896+5040 = 6936, sigma(1727+5040) = sigma(6767) = 1+67+101+6767 = 6936.
%e a(2) = A054799(24) = 434, a(3) = A015914(19) = 104, the first composites in that series.
%t L = {}; Do[i = 1; While[ ! ((Plus @@ Divisors[i + j! ] == j! + Plus @@ Divisors[i]) && ! PrimeQ[i]), i++ ]; L = Append[L, i], {j, 2, 13}]; L (from Vit Planocka)
%Y Cf. A054904, A054905, A054799, A015914, A033560.
%K more,nonn
%O 2,1
%A _Labos Elemer_, May 29 2000
%E More terms from Vit Planocka (planocka(AT)mistral.cz), Sep 22 2003
%E a(14)-a(19) from _Donovan Johnson_, Nov 30 2008
%E a(20) from _Donovan Johnson_, Sep 19 2013
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