cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A259729 Sum of digits of a(n) equals the sum of digits of 5*a(n).

Original entry on oeis.org

0, 9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108, 126, 144, 162, 180, 189, 198, 207, 216, 225, 234, 243, 252, 261, 270, 279, 297, 306, 324, 342, 360, 369, 378, 387, 396, 405, 414, 423, 432, 441, 450, 459, 477, 495, 504, 522, 540, 549, 558, 567, 576, 585, 594
Offset: 1

Views

Author

Christina Steffan, Jul 05 2015

Keywords

Comments

A007953(a(n)) = A007953(5*a(n)).
a(n) is a multiple of 9, but not all multiples of 9 belong to the sequence: 117 = 13*9: A007953(117) = 1 + 1 + 7 = 9, but A007953(5*117) = A007953(585) = 5 + 8 + 5 = 18.

Examples

			18 belongs to the sequence, because A007953(18) = 9 = A007953(90) = A007953(5*18).
		

Crossrefs

Programs

  • Magma
    [n: n in [0..800] | &+Intseq(n) eq &+Intseq(5*n)]; // Vincenzo Librandi, Aug 05 2015
  • Mathematica
    Select[Range[0, 600], Total@ IntegerDigits@ # == Total@ IntegerDigits[5 #] &] (* Michael De Vlieger, Aug 05 2015 *)