A393803 Numbers whose number of nonzero digits is identical in base 2 and 3.

0, 1, 2, 5, 10, 12, 13, 14, 20, 22, 24, 25, 26, 33, 35, 36, 37, 38, 42, 43, 53, 69, 71, 72, 73, 74, 77, 88, 100, 106, 113, 116, 120, 121, 122, 124, 137, 138, 139, 142, 147, 150, 151, 154, 156, 157, 158, 178, 184, 197, 201, 203, 204, 205, 206, 209, 210, 211, 214, 226, 228, 229

Offset

1,3

Links

Vincenzo Manto, Table of n, a(n) for n = 1..9999

Maple

q:= n-> (f-> f(n, 2)=f(n, 3))((k, b)-> nops(subs(0=[][], convert(k, base, b)))):
select(q, [$0..230])[];  # Alois P. Heinz, Apr 01 2026

Mathematica

q[k_] := DigitCount[k, 2, 1] == Total[DigitCount[k, 3, {1, 2}]]; Select[Range[0, 230], q] (* Amiram Eldar, Mar 29 2026 *)

Prog

(Python)
def nonzero_digits(n, b):
    count = 0
    while n > 0:
        if n % b: count += 1
        n //= b
    return count
def ok(n):
    return nonzero_digits(n, 2) == nonzero_digits(n, 3)
print([k for k in range(230) if ok(k)]) # Vincenzo Manto, Apr 08 2026

Crossrefs

Cf. A000120, A160384.

Sequence in context: A018514 A018288 A245480 * A080792 A351062 A182656

Adjacent sequences: A393800 A393801 A393802 * A393804 A393805 A393806

Keyword

nonn,base

Author

Vincenzo Manto, Mar 29 2026

Status

approved