A373184 - OEIS

%I #24 May 27 2024 22:39:51

%S 2,3,6,5,6,10,8,9,16,11,12,18,14,15,22,17,18,29,20,21,30,23,24,34,26,

%T 27,44,29,30,42,32,33,46,35,36,55,38,39,54,41,42,58,44,45,68,47,48,66,

%U 50,51,70,53,54,84,56,57,78,59,60,82,62,63,94,65,66,90,68,69,94,71,72,107,74,75,102,77,78,106,80,81

%N G.f. A(x) satisfies A(x) = 1/(1 - x)^2 - 1 + A(x^3).

%H Seiichi Manyama, <a href="/A373184/b373184.txt">Table of n, a(n) for n = 1..10000</a>

%F a(3*n+1) = 3*n+2, a(3*n+2) = 3*n+3 and a(3*n+3) = 3*n+4 + a(n+1) for n >= 0.

%F G.f.: A(x) = Sum_{k>=0} (1/(1 - x^(3^k))^2 - 1).

%o (Ruby)

%o def A(k, n)

%o   ary = [0]

%o   (1..n).each{|i|

%o     j = i + 1

%o     j += ary[i / k] if i % k == 0

%o     ary << j

%o   }

%o   ary[1..-1]

%o end

%o p A(3, 80)

%Y Cf. A084432, A373185.

%Y Cf. A327625.

%K nonn,easy

%O 1,1

%A _Seiichi Manyama_, May 27 2024