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S(1)={1}. S(n) = {S(n-1) {1,2,...,(n-1),n,(n-1),...,2,1} S(n-1)}, where S(n) is a string of the first 3*2^n -2*n -3 terms of the sequence.
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%I #15 May 09 2024 02:39:40

%S 1,1,2,1,1,1,2,3,2,1,1,1,2,1,1,1,2,3,4,3,2,1,1,1,2,1,1,1,2,3,2,1,1,1,

%T 2,1,1,1,2,3,4,5,4,3,2,1,1,1,2,1,1,1,2,3,2,1,1,1,2,1,1,1,2,3,4,3,2,1,

%U 1,1,2,1,1,1,2,3,2,1,1,1,2,1,1,1,2,3,4,5,6,5,4,3,2,1,1,1,2,1,1,1,2,3,2,1,1

%N S(1)={1}. S(n) = {S(n-1) {1,2,...,(n-1),n,(n-1),...,2,1} S(n-1)}, where S(n) is a string of the first 3*2^n -2*n -3 terms of the sequence.

%C S(n) consists of the first 3*2^n - 2*n - 3 terms of the sequence, i.e., S(n) consists of A050488(n) terms.

%C Each S(n) forms a palindrome.

%H John Tyler Rascoe, <a href="/A126863/b126863.txt">Table of n, a(n) for n = 1..6119</a>

%e S(1) = {1}.

%e S(2) = {1,1,2,1,1}.

%e S(3) = {1,1,2,1,1,1,2,3,2,1,1,1,2,1,1}.

%e S(4) = {1,1,2,1,1,1,2,3,2,1,1,1,2,1,1,1,2,3,4,3,2,1,1,1,2,1,1,1,2,3,2,1,1,1,2,1,1},

%e etc.

%Y Cf. A050488.

%K easy,nonn

%O 1,3

%A _Leroy Quet_, Mar 15 2007