|
| |
|
|
A118468
|
|
Numbers n for which the sum of the digits plus the sum of the digits of the square, equals the sum of the digits of the cube.
|
|
0
| |
|
|
0, 9, 18, 27, 36, 45, 54, 72, 90, 99, 108, 135, 162, 180, 189, 198, 216, 225, 243, 270, 288, 306, 315, 333, 360, 405, 432, 441, 450, 495, 504, 513, 522, 531, 540, 594, 603, 612, 621, 639, 648, 657, 666, 675, 720, 765, 783, 801, 819, 837, 846, 855, 873, 882
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| s(n) stands for the sum of the digits of n.
|
|
|
FORMULA
| s(n)+s(n^2)=s(n^3)
|
|
|
EXAMPLE
| 45 is in the sequence because (1) the sum of the digits is 4+5=9, (2) the sum of the digits of 45^2 = 2025 is 2+0+2+5=9, (3) the sum of the digits of 45^3=91125 is 9+1+1+2+5=18 and (4) 9+9=18
|
|
|
MATHEMATICA
| dgsQ[n_]:=Total[IntegerDigits[n]]+Total[IntegerDigits[n^2]]== Total[ IntegerDigits[ n^3]]; Select[Range[0, 900], dgsQ] (* From Harvey P. Dale, Aug 02 2011 *)
|
|
|
CROSSREFS
| Sequence in context: A020336 A044834 A033006 * A206905 A083497 A067552
Adjacent sequences: A118465 A118466 A118467 * A118469 A118470 A118471
|
|
|
KEYWORD
| base,nonn
|
|
|
AUTHOR
| Luc Stevens (lms022(AT)yahoo.com), May 04 2006
|
| |
|
|
