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A269572
Maximal period-length associated with binary fractility of n.
2
1, 1, 1, 2, 1, 2, 1, 3, 2, 5, 1, 6, 2, 3, 1, 4, 3, 9, 2, 4, 5, 7, 1, 10, 6, 9, 2, 14, 3, 4, 1, 5, 4, 7, 3, 18, 9, 8, 2, 10, 4, 7, 5, 7, 7, 14, 1, 11, 10, 6, 6, 26, 9, 12, 2, 9, 14, 29, 3, 30, 4, 5, 1, 6, 5, 33, 4, 11, 7, 21, 3, 6, 18, 11, 9, 15, 8, 22, 2, 27
OFFSET
2,4
COMMENTS
For each x in (0,1], let 1/2^p(1) + 1/2^p(2) + ... be the infinite binary representation of x. Let d(1) = p(1) and d(i) = p(i) - p(i-1) for i >=2. Call (d(i)) the powerdifference sequence of x, and denote it by D(x). Call m/n and u/v equivalent if every period of D(m/n) is a period of D(u/v). Define the binary fractility of n to be the number of distinct equivalence classes of {m/n: 0 < m < n}. Each class is represented by a minimal period, and a(n) is the length of the longest such period.
EXAMPLE
n classes a(n)
2 (1) 1
3 (2) 1
4 (1) 1
5 (1,3) 2
6 (1), (2) 1
7 (1,2), (3) 2
8 (1) 1
9 (1), (1,1,4) 3
10 (1), (1,3) 1
CROSSREFS
Sequence in context: A226517 A185214 A241719 * A029198 A029175 A186994
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Mar 01 2016
STATUS
approved