A098769 Abundant numbers whose reversal is also an abundant number.

24, 42, 48, 66, 84, 88, 204, 210, 216, 222, 228, 234, 240, 246, 252, 258, 264, 270, 272, 276, 282, 288, 294, 402, 408, 414, 420, 426, 432, 438, 444, 450, 456, 462, 464, 468, 474, 480, 486, 492, 498, 606, 612, 616, 618, 624, 630, 636, 642, 648, 650, 654, 660

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

a(1)=24 because 24 and the reversal of 24, i.e. 42, are abundant numbers.

Mathematica

anrQ[n_]:=Module[{rn=FromDigits[Reverse[IntegerDigits[n]]]}, DivisorSigma[ 1, n]>2n&&DivisorSigma[1, rn]>2rn]; Select[Range[700], anrQ] (* Harvey P. Dale, Jun 27 2012 *)

Crossrefs

Cf. A005101.

Sequence in context: A007372 A062910 A098900 * A162886 A274350 A063702

Adjacent sequences: A098766 A098767 A098768 * A098770 A098771 A098772

Keyword

easy,nonn,base

Author

Shyam Sunder Gupta, Oct 02 2004

Extensions

Edited by N. J. A. Sloane, Apr 29 2007

Status

approved