A049341 a(n+1) = sum of digits of a(n) + a(n-1).

3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3, 3, 6, 9, 6, 6, 3, 9, 3

Offset: 0

Author

Damir Olejar

Keywords

• base
• nonn
• easy

Comments

a(n+1) = A007953(a(n) + a(n-1)) for n > 0.

Examples

			After 6,9 we get 6+9 = 15 -> 1+5 = 6.
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
• Michael Gilleland, Some Self-Similar Integer Sequences
• Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 1).

Crossrefs

Cf. A030132, A030133, A049342.

Programs

Haskell

a049341 n =  a030132_list !! n
a049341_list =
   3 : 6 : map a007953 (zipWith (+) a049341_list $ tail a049341_list)
-- Reinhard Zumkeller, Aug 20 2011

Mathematica

LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 1},{3, 6, 9, 6, 6, 3, 9, 3},112] (* Ray Chandler, Aug 27 2015 *)

Formula

Period 8.

Extensions

Definition improved by Reinhard Zumkeller, Aug 20 2011