A167430 - OEIS

%I #4 Apr 06 2020 20:39:22

%S 1,2,1,3,2,4,1,3,5,2,4,6,1,3,5,7,2,4,6,8,1,3,5,7,9,2,4,6,8,10,1,3,5,7,

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

%U 15,2,4,6,8,10,12,14,16,1,3,5,7,9,11,13,15,17,2,4,6,8,10,12,14,16,18,1,3,5,7

%N Fractal sequence of the interspersion A163255.

%C Both the upper trim and the lower trim of A167430 are identical to A167430.

%C (The upper trim of a fractal sequence s is what remains after the first

%C occurrence of each term is deleted; the lower trim of s is what remains

%C after all 0's are deleted from the sequence s-1.)

%F The sequence is formed by concatenating rows:

%F Row 1: ... 1 2

%F Row 2: ... 1 3 2 4

%F Row 3: ... 1 3 5 2 4 6

%F Row n comes from row n-1 by putting 2n-1 just before 2 and 2*n

%F just after 2n-2.

%Y Cf. A002260, A163255.

%K nonn

%O 1,2

%A _Clark Kimberling_, Nov 03 2009