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A080941
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Greatest proper divisor of n which is a suffix of n in binary representation; a(n) = 0 if no such divisor exists.
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9
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0, 0, 1, 0, 1, 2, 1, 0, 1, 2, 1, 4, 1, 2, 3, 0, 1, 2, 1, 4, 1, 2, 1, 8, 1, 2, 3, 4, 1, 6, 1, 0, 1, 2, 1, 4, 1, 2, 3, 8, 1, 2, 1, 4, 5, 2, 1, 16, 1, 2, 3, 4, 1, 6, 1, 8, 1, 2, 1, 12, 1, 2, 7, 0, 1, 2, 1, 4, 1, 2, 1, 8, 1, 2, 3, 4, 1, 6, 1, 16, 1, 2, 1, 4, 5, 2, 3, 8, 1, 10, 1, 4, 1, 2, 1, 32, 1, 2, 3, 4, 1, 6, 1
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refs;
listen;
history;
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OFFSET
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1,6
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COMMENTS
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LINKS
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EXAMPLE
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n=30='11110', divisors<30: 1='1', 2='10', 3='11', 5='101', 6='110', 10='1010' and 15='1111', therefore a(30)=2='10';
n=31='11111', divisors<31: 1='1', therefore a(31)=1;
n=32='100000', divisors<32: 1='1', 2='10', 4='100', 8='1000' and 16='10000', therefore a(32)=0.
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PROG
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(Haskell)
import Data.List (isPrefixOf); import Data.Function (on)
a080941 n = if null ds then 0 else head ds where
ds = filter ((flip isPrefixOf `on` a030308_row) n) $
reverse $ a027751_row n
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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