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%I #9 Jul 14 2015 01:10:50
%S 3,9,2,6,3,9,4,6,3,9,2,6,3,7,9,6,8,3,7,9,6,1,3,5,9,4,6,3,9,6,3,5,9,6,
%T 3,7,9,6,3,5,9,6,3,7,9,2,6,1,3,9,4,6,8,3,9,6,3,9,6,8,3,9,2,6,1,3,9,6,
%U 3,7,9,2,6,3,5,9,6,3,7,9,6,8,1,3,9,4,6,8,3,9,2,6,3,5,9,4,6,3,9,2,6,3,9,6,8
%N Digital root of n-th abundant number.
%e The 11th abundant number is 56. 5+6=11. 1+1=2. The digital root is 2.
%t abQ[n_] := DivisorSigma[1, n] > 2 n; Mod[ Select[ Range@ 500, abQ], 9] /. 0 -> 9 (* _Robert G. Wilson v_, Aug 23 2010 *)
%Y Cf. A005101.
%K nonn,base
%O 1,1
%A _Jason G. Wurtzel_, Jul 22 2010
%E More terms from _Robert G. Wilson v_, Aug 23 2010
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