A043705 Numbers whose base-16 representation has an even number of runs.

16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base

Programs

Python

from itertools import groupby
def ok(n): return len(list(g for k, g in groupby(hex(n)[2:])))%2 == 0
print(list(filter(ok, range(1, 80)))) # Michael S. Branicky, Jun 18 2021