A037970 Numbers whose maximal base-2 run length is 3.

7, 8, 14, 17, 23, 24, 28, 29, 34, 35, 39, 40, 46, 49, 55, 56, 57, 58, 59, 68, 69, 70, 71, 72, 78, 81, 87, 88, 92, 93, 98, 99, 103, 104, 110, 113, 114, 115, 116, 117, 118, 119, 136, 137, 138, 139, 140, 141, 142, 145, 151, 152, 156, 157, 162, 163, 167, 168, 174

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A007088.

Subsequence of A136037.

Programs

Python

def ok(n):
    b = bin(n)[2:]
    return ("000" in b or "111" in b) and not ("0000" in b or "1111" in b)
print(list(filter(ok, range(175)))) # Michael S. Branicky, Jul 08 2021

Extensions

a(55) and beyond from Michael S. Branicky, Jul 08 2021