A064806 a(n) = n + digital root of n.

2, 4, 6, 8, 10, 12, 14, 16, 18, 11, 13, 15, 17, 19, 21, 23, 25, 27, 20, 22, 24, 26, 28, 30, 32, 34, 36, 29, 31, 33, 35, 37, 39, 41, 43, 45, 38, 40, 42, 44, 46, 48, 50, 52, 54, 47, 49, 51, 53, 55, 57, 59, 61, 63, 56, 58, 60, 62, 64, 66, 68, 70, 72, 65, 67, 69, 71

Offset

1,1

Links

Harry J. Smith, Table of n, a(n) for n=1..1000

Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,0,1,-1).

Index entries for Colombian or self numbers and related sequences

Formula

a(n) = n + A010888(n).

G.f.: -x*(9*x^9-2*x^8-2*x^7-2*x^6-2*x^5-2*x^4-2*x^3-2*x^2-2*x-2) / ((x-1)^2*(x^2+x+1)*(x^6+x^3+1)). - Colin Barker, Apr 05 2013

Maple

A064806 := proc(n) return n+1 + ((n-1) mod 9): end: seq(A064806(n), n=1..100); # Nathaniel Johnston, May 04 2011

Mathematica

Table[n+Mod[n-1, 9]+1, {n, 70}] (* or *) LinearRecurrence[{1, 0, 0, 0, 0, 0, 0, 0, 1, -1}, {2, 4, 6, 8, 10, 12, 14, 16, 18, 11}, 70] (* Harvey P. Dale, Nov 19 2022 *)

Prog

(PARI) { for (n=1, 1000, write("b064806.txt", n, " ", n + (n - 1)%9 + 1) ) } \\ Harry J. Smith, Sep 26 2009
(Haskell)
a064806 n = n + a010888 n  -- Reinhard Zumkeller, Apr 13 2013

Crossrefs

Cf. A010888 (digital root of n), A062028 (sum of digits of n).

Sequence in context: A182324 A095815 A063114 * A062028 A262223 A070196

Adjacent sequences: A064803 A064804 A064805 * A064807 A064808 A064809

Keyword

nonn,easy,base

Author

Reinhard Zumkeller, Oct 21 2001

Status

approved