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A043705
Numbers whose base-16 representation has an even number of runs.
3
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
1,1
PROG
(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
CROSSREFS
Sequence in context: A358677 A085096 A043675 * A374594 A178980 A031315
KEYWORD
nonn,base
STATUS
approved