OFFSET
1,1
COMMENTS
This sequence is a variant of A361818.
If k belongs to the sequence, then A004488(k) belongs to the sequence.
The ternary lengths of terms belong to A007494 (as the number of values in triangles must be divisible by 3).
This sequence is infinite as it contains the numbers whose ternary digits match the regular expression "(210)+".
Empirically, there are 4*3^floor((w-1)/2) terms with w ternary digits.
No term belongs to A297250.
LINKS
EXAMPLE
The ternary expansion of 149 is "12112", and the corresponding triangle is:
0
1 2
0 2 2
0 0 1 0
1 2 1 1 2
The configurations of 0's, 1's and 2's are the same up to rotation, so 149 belongs to this sequence:
0 . .
. . 1 . . 2
0 . . . . . . 2 2
0 0 . 0 . . 1 . . . . .
. . . . . 1 . 1 1 . . 2 . . 2
PROG
(PARI) See Links section.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Mar 26 2023
STATUS
approved