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Length of n-th term of A321225.
2

%I #23 Apr 24 2024 08:12:57

%S 1,1,1,3,2,4,4,4,5,6,6,6,8,7,9,9,9,10,11,11,11,13,12,14,14,14,15,16,

%T 16,16,18,17,19,19,19,20,21,21,21,23,22,24,24,24,25,26,26,26,28,27,29,

%U 29,29,30,31,31,31,33,32,34,34,34,35,36,36,36,38,37,39,39,39,40

%N Length of n-th term of A321225.

%H Seiichi Manyama, <a href="/A321232/b321232.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,0,0,0,0,0,1,-1).

%F a(n) = a(n-9) + 5, for n > 9.

%F G.f.: x*(x^8 + 2*x^5 - x^4 + 2*x^3 + 1)/(x^10 - x^9 - x + 1). - _Chai Wah Wu_, Jan 06 2020

%e n | A321225 | a(n)

%e --+---------+-----

%e 1 | 1 | 1

%e 2 | 2 | 1

%e 3 | 3 | 1

%e 4 | 211 | 3

%e 5 | 23 | 2

%e 6 | 2112 | 4

%e 7 | 3211 | 4

%e 8 | 2321 | 4

%e 9 | 12321 | 5

%t LinearRecurrence[{1, 0, 0, 0, 0, 0, 0, 0, 1, -1}, {1, 1, 1, 3, 2, 4, 4, 4, 5, 6}, 100] (* _Paolo Xausa_, Apr 24 2024 *)

%Y Cf. A068962, A321225.

%K nonn,easy

%O 1,4

%A _Seiichi Manyama_, Oct 31 2018