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A064894
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Binary dilution of n. GCD of exponents in binary expansion of n.
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3
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0, 0, 1, 1, 2, 2, 1, 1, 3, 3, 1, 1, 1, 1, 1, 1, 4, 4, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, 6, 1, 1, 2, 2, 1, 1, 3, 3, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,5
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COMMENTS
| All bits of n in positions not divisible by a(n) are zero. Hence n in binary contains blocks of a(n)-1 "diluting" 0's (for n>1). Also for n>1, a(2^n) = a(2^n + 1) = n. For i,j odd, a(ij) = GCD(a(i),a(j)).
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FORMULA
| If n = 2^e0 + 2^e1 +... then a(n) = GCD(e0, e1, ...).
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EXAMPLE
| 577 = 2^0 + 2^6 + 2^9, GCD(0,6,9) = 3 = a(577)
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CROSSREFS
| A000079, A064895.
a(A064896(n)) = A056538(n)
Sequence in context: A057060 A198380 A152805 * A003638 A094267 A136480
Adjacent sequences: A064891 A064892 A064893 * A064895 A064896 A064897
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KEYWORD
| base,easy,nonn
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AUTHOR
| Marc LeBrun (mlb(AT)well.com), Oct 11 2001
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