A350573 Base-10 version of A038103 interpreted as base 3.

0, 1, 2, 3, 6, 7, 11, 12, 21, 22, 23, 24, 31, 41, 43, 62, 145, 146, 149, 152, 2626, 2627, 4370, 8463, 8466, 13562, 20841, 42320, 43171, 46609, 47749, 48150, 52723, 55179, 55180, 55181

Offset: 1

Author

Hans Havermann, Jan 06 2022

Keywords

• nonn
• base

Links

• Hans Havermann, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A038103, A350572.

Programs

Mathematica

B3[n_] := FromDigits[IntegerDigits[n, 3]]
SP[n_] := (b = B3[n]; StringPosition[ToString[B3[b]], ToString[b]])
n=0; t={}; While[n<10^6, If[SP[n]!={}, AppendTo[t, n]]; n++]; t

Python

from sympy.ntheory.digits import digits
from itertools import count, islice, product
def agen(): # generator of terms
    yield 0
    for d in count(1):
        for first in "12":
            for rest in product("012", repeat=d-1):
                s = first + "".join(rest)
                if s in "".join(str(d) for d in digits(int(s), 3)[1:]):
                    yield int(s, 3)
print(list(islice(agen(), 36))) # Michael S. Branicky, Jan 06 2022

Python

from itertools import count, islice
from gmpy2 import digits
def A350573_gen(): return (n for n in count(0) if (s:=digits(n,3)) in digits(int(s),3))
A350573_list = list(islice(A350573_gen(),30)) # Chai Wah Wu, Jan 09 2022