A393803
Numbers whose number of nonzero digits is identical in base 2 and 3.
Sequence Chart
Data
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
Computational Implementations
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 Mathematica
q[k_] := DigitCount[k, 2, 1] == Total[DigitCount[k, 3, {1, 2}]]; Select[Range[0, 230], q] (* _Amiram Eldar_, Mar 29 2026 *) Cross-References
See also OEIS entries: Cf. A000120, A160384.