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A171400 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. 5
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,9

COMMENTS

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.

LINKS

R. Zumkeller, Table of n, a(n) for n = 0..2500

Michael Gilleland, Levenshtein Distance

Wikipedia, Levenshtein Distance

FORMULA

a(n) = BinaryLevenshteinDistance(n, A007918(n)).

EXAMPLE

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.

CROSSREFS

Cf. A007088, A007920.

Sequence in context: A204459 A035155 A090584 * A271592 A128409 A133699

Adjacent sequences:  A171397 A171398 A171399 * A171401 A171402 A171403

KEYWORD

base,nonn

AUTHOR

Reinhard Zumkeller, Dec 08 2009

STATUS

approved

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Last modified November 30 06:11 EST 2020. Contains 338781 sequences. (Running on oeis4.)