A171181 n followed by (n - sum of digits of n).

0, 0, 1, 0, 2, 0, 3, 0, 4, 0, 5, 0, 6, 0, 7, 0, 8, 0, 9, 0, 10, 9, 11, 9, 12, 9, 13, 9, 14, 9, 15, 9, 16, 9, 17, 9, 18, 9, 19, 9, 20, 18, 21, 18, 22, 18, 23, 18, 24, 18, 25, 18, 26, 18, 27, 18, 28, 18, 29, 18, 30, 27, 31, 27, 32, 27, 33, 27, 34, 27, 35, 27, 36, 27, 37, 27, 38, 27, 39, 27

Offset: 0

Author

Marcel Hetkowski Fabeny (marcelfabeny(AT)yahoo.com.br), Dec 04 2009

Keywords

• easy
• nonn
• base

Examples

			a(0) = 0, a(1) = 0 - 0 = 0.
a(2) = 1, a(3) = 1 - 1 = 0.
a(4) = 2, a(5) = 2 - 2 = 0.
a(6) = 3, a(7) = 3 - 3 = 0.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..1000

Crossrefs

Interspersion of A001477 and A066568.

Programs

Mathematica

Table[{n,n-Total[IntegerDigits[n]]},{n,0,40}]//Flatten (* Harvey P. Dale, Nov 26 2016 *)

PARI

a(n) = if (n % 2 == 0, n/2, nn = n\2; d = digits(nn); nn - sum(i=1, #d, d[i]);); \\ Michel Marcus, Aug 14 2013

Formula

If n is even, a(n) = n/2; if n is odd, a(n) = A066568(floor(n/2)). - Michel Marcus, Aug 14 2013

Extensions

Edited by N. J. A. Sloane, Dec 05 2009