

A147755


a(n) = the largest integer that, when represented in binary, occurs at least twice as a substring in the binary representation of n.


3



1, 0, 1, 1, 3, 0, 1, 2, 1, 1, 1, 3, 7, 0, 1, 2, 1, 2, 5, 2, 3, 1, 1, 2, 3, 3, 3, 7, 15, 0, 1, 2, 1, 4, 2, 2, 3, 2, 2, 10, 5, 2, 5, 3, 7, 1, 1, 2, 3, 2, 5, 6, 3, 3, 3, 3, 3, 7, 7, 15, 31, 0, 1, 2, 1, 4, 2, 2, 3, 4, 9, 2, 2, 4, 2, 3, 7, 2, 2, 2, 2, 10, 21, 5, 5, 2, 2, 5, 11, 3, 5, 7, 15, 1, 1, 2, 3, 4, 2, 6, 3, 2
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OFFSET

3,5


COMMENTS

The substrings (each equal to the binary representation of a(n)) may overlap in the binary representation of n.


LINKS

Alois P. Heinz, Table of n, a(n) for n = 3..8190


EXAMPLE

21 in binary is 10101. 101 (5 in decimal) occurs twice in 10101: (101)01 and 10(101). Since no larger integer (when represented in binary) occurs more than once within 10101, then a(21) = 5.


MATHEMATICA

Table[With[{d = IntegerDigits[n, 2]}, SelectFirst[Range[n, 0, 1], SequenceCount[d, IntegerDigits[#, 2], Overlaps > True] >= 2 &]], {n, 3, 104}] (* Michael De Vlieger, Oct 30 2017 *)


CROSSREFS

Cf. A147756, A242869.
Sequence in context: A242869 A224878 A129555 * A307195 A231188 A249695
Adjacent sequences: A147752 A147753 A147754 * A147756 A147757 A147758


KEYWORD

base,nonn,look


AUTHOR

Leroy Quet, Nov 11 2008


EXTENSIONS

Extended by Ray Chandler, Nov 14 2008


STATUS

approved



