A330416 - OEIS

%I #9 Dec 14 2019 19:26:07

%S 0,1,2,2,3,4,3,3,4,6,5,3,2,5,7,5,4,4,7,8,6,3,3,8,12,8,4,4,9,12,7,3,5,

%T 10,11,5,2,6,9,7,5,6,10,10,7,6,8,10,9,8,7,8,12,12,10,8,9,12,11,9,7,7,

%U 13,16,9,2,7,11,14,12,4,7,13,17,12,3,8,15,16,9

%N a(n) = (number of times a(n-2) has already appeared) + (number of times a(n-3) has already appeared), starting with a(n) = n for n<3.

%C This sequence is a variant of A330332.

%C This sequence appears to diverge much more slowly than A330332.

%H Rémy Sigrist, <a href="/A330416/a330416.txt">C program for A330416</a>

%H Rémy Sigrist, <a href="/A330416/a330416.png">Density plot of the first 100000000 terms</a>

%e a(0) = 0.

%e a(1) = 1.

%e a(2) = 2.

%e For n = 3:

%e - a(1) = 1 has appeared once, a(0) = 0 has appeared once,

%e - hence a(3) = 1+1 = 2.

%e For n = 4:

%e - a(2) = 2 has appeared twice, a(1) = 1 has appeared once,

%e - hence a(4) = 2+1 = 3.

%t Nest[Append[#, Count[#, #[[-2]] ] + Count[#, #[[-3]] ]] &, {0, 1, 2}, 77] (* _Michael De Vlieger_, Dec 14 2019 *)

%o (C) See Links section.

%Y Cf. A330332.

%K nonn

%O 0,3

%A _Rémy Sigrist_, Dec 14 2019