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A371111
Ternary numbers that are concatenated runs C(1)A(1)B(1)C(2)A(2)B(2)...C(k)A(k)B(k), where A(i) is a run of 1's, B(i) a run of 0's, and C(i) a run of 2's, for i = 1..k.
7
210, 2100, 2110, 2210, 21000, 21100, 21110, 22100, 22110, 22210, 210000, 210210, 211000, 211100, 211110, 221000, 221100, 221110, 222100, 222110, 222210, 2100000, 2100210, 2102100, 2102110, 2102210, 2110000, 2110210, 2111000, 2111100, 2111110, 2210000
OFFSET
1,1
MATHEMATICA
Map[#[[1]] &, Select[Map[{#, DeleteDuplicates[Partition[Map[#[[1]] &, Split[IntegerDigits[#, 3]]], UpTo[3]]] == {{2, 1, 0}}} &,
Range[3, 3600, 3]], #[[2]] &]] (* this sequence *)
m = Map[{#, IntegerString[#, 3]} &, %];
Map[Last, ToExpression[m]] (* A371112 *)
(* Peter J. C. Moses, Mar 06 2024 *)
KEYWORD
nonn,base
AUTHOR
Clark Kimberling, Mar 31 2024
STATUS
approved