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A064806
a(n) = n + digital root of n.
7
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
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
KEYWORD
nonn,easy,base
AUTHOR
Reinhard Zumkeller, Oct 21 2001
STATUS
approved