A160939 a(n) = n + digital sum (n-1).

1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 78

Offset: 1

Author

Claudio Meller, May 30 2009

Keywords

• nonn
• base

Examples

			Writing ds() for the sum of digits (A007953),
a(8) = 8 + ds(7) = 8 + 7 = 15,
a(15) = 15 + ds(14) = 15 + 5 = 20,
a(26) = 26 + ds(25) = 26 + 7 = 33.
		

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A007953, A062028.

Programs

Magma

[n + &+Intseq(n-1): n in [1..80]]; // Vincenzo Librandi, Nov 09 2018

Mathematica

Table[n+Total[IntegerDigits[n-1]],{n,80}] (* Harvey P. Dale, Dec 08 2012 *)

PARI

a(n) = n + sumdigits(n-1); \\ Michel Marcus, Aug 02 2018

Python

def A160939(n): return n+sum(map(int,str(n-1))) # Chai Wah Wu, Aug 09 2025

Formula

a(n+1) = A062028(n) + 1 for n >= 1. - Michel Marcus, Aug 02 2018