A070279 Sum of digits of n equals the sum of digits of 2n.

9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108, 117, 126, 135, 153, 162, 171, 180, 189, 198, 207, 216, 225, 252, 261, 270, 279, 288, 297, 306, 315, 351, 360, 369, 378, 387, 396, 405, 450, 459, 468, 477, 486, 495, 504, 513, 522, 531, 540, 549, 594, 603, 612

Offset: 1

Author

Benoit Cloitre, May 09 2002

Keywords

• easy
• nonn
• base

Comments

A010888(a(n)) = 9, but not all multiples of 9 belong to the sequence: e.g. 144=16*9: A007953(144)=1+4+4=9, but A007953(144*2)=A007953(288)=2+8+8=18. - Reinhard Zumkeller, May 15 2002

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Programs

Mathematica

Select[Range[1000],Total[IntegerDigits[#]]==Total[IntegerDigits[ 2#]]&] (* Harvey P. Dale, Jul 22 2011 *)

PARI

is(n)=sumdigits(n)==sumdigits(2*n) \\ Charles R Greathouse IV, Jun 17 2012

Extensions

Incorrect comment removed by Charles R Greathouse IV, Jun 17 2012