cp's OEIS Frontend

A120150 a(n) = 3 + floor((2 + Sum_{j=1..n-1} a(j))/3).

%I A120150 #7 Jun 05 2023 08:52:49
%S A120150 3,4,6,8,10,14,18,24,32,43,57,76,102,136,181,241,322,429,572,763,1017,
%T A120150 1356,1808,2411,3214,4286,5714,7619,10159,13545,18060,24080,32107,
%U A120150 42809,57079,76105,101473,135298,180397,240529
%N A120150 a(n) = 3 + floor((2 + Sum_{j=1..n-1} a(j))/3).
%H A120150 G. C. Greubel, <a href="/A120150/b120150.txt">Table of n, a(n) for n = 1..1000</a>
%t A120150 A120150[n_]:= A120150[n]= 3 +Quotient[2 +Sum[A120150[k], {k,n-1}], 3];
%t A120150 Table[A120150[n], {n, 60}] (* _G. C. Greubel_, Jun 04 2023 *)
%o A120150 (SageMath)
%o A120150 @CachedFunction
%o A120150 def A120150(n): return 3 + (2+sum(A120150(k) for k in range(1,n)))//3
%o A120150 [A120150(n) for n in range(1, 61)] # _G. C. Greubel_, Jun 04 2023
%Y A120150 Cf. A072493, A073941, A112088.
%K A120150 nonn
%O A120150 1,1
%A A120150 _Graeme McRae_, Jun 10 2006