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A171400
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Minimal number of editing steps (delete, insert or substitute) to transform the binary representation of n into that of A007918(n), the least prime not less than n.
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5
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1, 1, 0, 0, 1, 0, 1, 0, 2, 1, 1, 0, 1, 0, 3, 3, 1, 0, 1, 0, 2, 1, 1, 0, 2, 1, 2, 2, 1, 0, 1, 0, 2, 1, 2, 2, 1, 0, 3, 3, 1, 0, 1, 0, 2, 1, 1, 0, 2, 1, 2, 2, 1, 0, 2, 2, 2, 1, 1, 0, 1, 0, 5, 4, 2, 1, 1, 0, 2, 1, 1, 0, 1, 0, 2, 1, 2, 1, 1, 0, 2, 1, 1, 0, 2, 2, 3, 3, 1, 0, 4, 4, 4, 4, 5, 5, 1, 0, 2, 2, 1, 0, 1, 0, 2
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OFFSET
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0,9
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COMMENTS
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Delete steps are not necessary;
a(n) = 0 iff n is prime: a(A000040(n))=0;
a(A171401(n)) = 1;
A171402 gives smallest numbers m such that a(m)=n: a(A171402(n))=n.
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LINKS
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R. Zumkeller, Table of n, a(n) for n = 0..2500
Michael Gilleland, Levenshtein Distance
Wikipedia, Levenshtein Distance
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FORMULA
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a(n) = BinaryLevenshteinDistance(n, A007918(n)).
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EXAMPLE
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n=14, A007918(14)=17: 14==1110->1100->1100->10001==17, 2 subst and 1 ins: a(14)=3;
n=15, A007918(15)=17: 15==1111->1011->1001->10001==17, 2 subst and 1 ins: a(15)=3;
n=16, A007918(16)=17: 16==10000->10001==17, 1 subst: a(16)=1, A171401(8)=16;
n=17, A007918(17)=17: no editing step: a(17)=0;
n=18, A007918(18)=19: 18==10010->10011==19, 1 subst: a(18)=1, A171401(9)=18.
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CROSSREFS
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Cf. A007088, A007920.
Sequence in context: A204459 A035155 A090584 * A128409 A133699 A157361
Adjacent sequences: A171397 A171398 A171399 * A171401 A171402 A171403
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KEYWORD
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base,nonn
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AUTHOR
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Reinhard Zumkeller, Dec 08 2009
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STATUS
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approved
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