cp's OEIS Frontend

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.

%I A171400 #3 Mar 30 2012 18:51:05
%S A171400 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,
%T A171400 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,
%U A171400 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
%N 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.
%C A171400 Delete steps are not necessary;
%C A171400 a(n) = 0 iff n is prime: a(A000040(n))=0;
%C A171400 a(A171401(n)) = 1;
%C A171400 A171402 gives smallest numbers m such that a(m)=n: a(A171402(n))=n.
%H A171400 R. Zumkeller, <a href="/A171400/b171400.txt">Table of n, a(n) for n = 0..2500</a>
%H A171400 Michael Gilleland, <a href="http://www.merriampark.com/ld.htm">Levenshtein Distance</a>
%H A171400 Wikipedia, <a href="http://en.wikipedia.org/wiki/Levenshtein_distance">Levenshtein Distance</a>
%F A171400 a(n) = BinaryLevenshteinDistance(n, A007918(n)).
%e A171400 n=14, A007918(14)=17: 14==1110->1100->1100->10001==17, 2 subst and 1 ins: a(14)=3;
%e A171400 n=15, A007918(15)=17: 15==1111->1011->1001->10001==17, 2 subst and 1 ins: a(15)=3;
%e A171400 n=16, A007918(16)=17: 16==10000->10001==17, 1 subst: a(16)=1, A171401(8)=16;
%e A171400 n=17, A007918(17)=17: no editing step: a(17)=0;
%e A171400 n=18, A007918(18)=19: 18==10010->10011==19, 1 subst: a(18)=1, A171401(9)=18.
%Y A171400 Cf. A007088, A007920.
%K A171400 base,nonn
%O A171400 0,9
%A A171400 _Reinhard Zumkeller_, Dec 08 2009