A371053 Ternary numbers consisting of a run of 2's, then a run of 1's, then a run of 0's.

210, 2100, 2110, 2210, 21000, 21100, 21110, 22100, 22110, 22210, 210000, 211000, 211100, 211110, 221000, 221100, 221110, 222100, 222110, 222210, 2100000, 2110000, 2111000, 2111100, 2111110, 2210000, 2211000, 2211100, 2211110, 2221000, 2221100, 2221110

Offset

1,1

Links

Table of n, a(n) for n=1..32.

Mathematica

Map[#[[1]] &, Select[Map[{#, Map[#[[1]] &, Split[IntegerDigits[#, 3]]] == {2, 1, 0}} &,
Range[0, 6000, 3]], #[[2]] &]] (* A371052 *)
ToExpression[Map[IntegerString[#, 3] &, %]]   (* this sequence *)
(* Peter J. C. Moses, Mar 06 2024 *)

Prog

(Python)
from itertools import count, islice
def A371053_gen(): # generator of terms
    return ((10**b*(10**a-1<<1)+10**b-1)//9*10**(l-a-b) for l in count(3) for a in range(1, l-1) for b in range(1, l-a))
A371053_list = list(islice(A371053_gen(), 20)) # Chai Wah Wu, Mar 21 2024

Crossrefs

Cf. A007089, A371052.

Sequence in context: A187309 A104902 A371111 * A135201 A187663 A064260

Adjacent sequences: A371050 A371051 A371052 * A371054 A371055 A371056

Keyword

nonn,base

Author

Clark Kimberling, Mar 17 2024

Status

approved