A179655 Digital root of n-th abundant number.

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, 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, 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

Offset

1,1

Links

Table of n, a(n) for n=1..105.

Example

The 11th abundant number is 56. 5+6=11. 1+1=2. The digital root is 2.

Mathematica

abQ[n_] := DivisorSigma[1, n] > 2 n; Mod[ Select[ Range@ 500, abQ], 9] /. 0 -> 9 (* Robert G. Wilson v, Aug 23 2010 *)

Crossrefs

Cf. A005101.

Sequence in context: A155080 A010780 A309275 * A357472 A076420 A091473

Adjacent sequences: A179652 A179653 A179654 * A179656 A179657 A179658

Keyword

nonn,base

Author

Jason G. Wurtzel, Jul 22 2010

Extensions

More terms from Robert G. Wilson v, Aug 23 2010

Status

approved