Question about A075849

[Eric W. Weisstein]

On Thu, 17 Oct 2002, Brian L. Galebach wrote:

> Looks like an error to me.

To me too...

FormatSequence[
  Table[n-If[n<2,2,Prime[PrimePi[n]]],{n,0,101}],
  75849,0,
  Name->"Distance to closest prime."
  ]

%I A075849 
%S A075849 2,1,0,0,1,0,1,0,1,2,3,0,1,0,1,2,3,0,1,0,1,2,3,0,1,2,3,4,5,0,1,0,1,2,
%T A075849 3,4,5,0,1,2,3,0,1,0,1,2,3,0,1,2,3,4,5,0,1,2,3,4,5,0,1,0,1,2,3,4,5,0,
%U A075849 1,2,3,0,1,0,1,2,3,4,5,0,1,2,3,0,1,2,3,4,5,0,1,2,3,4,5,6,7,0,1,2,3,0
%V A075849 -2,-1,0,0,1,0,1,0,1,2,3,0,1,0,1,2,3,0,1,0,1,2,3,0,1,2,3,4,5,0,1,0,1,2,
%W A075849 3,4,5,0,1,2,3,0,1,0,1,2,3,0,1,2,3,4,5,0,1,2,3,4,5,0,1,0,1,2,3,4,5,0,
%X A075849 1,2,3,0,1,0,1,2,3,4,5,0,1,2,3,0,1,2,3,4,5,0,1,2,3,4,5,6,7,0,1,2,3,0
%N A075849 Distance to closest prime.
%O A075849 0,1
%K A075849 sign,done
 
> -----Original Message-----
> From: Mark Hudson [mailto:mrmarkhudson at hotmail.com]
> Sent: Thursday, October 17, 2002 10:16 AM
> To: seqfan at ext.jussieu.fr
> Subject: Question about A075849
> 
> 
> Hi,
> 
> I've been lurking on this list for a while now for fear of looking stupid,
> but I have a query about A075849:
> 
> %I A075849
> %S A075849 2,1,0,0,1,0,1,0,1,2,1,0,1,2,1,0
> %N A075849 Distance to closest prime.
> %e A075849 a(34)=3
> %K A075849 nonn,more,new
> %O A075849 0,1
> 
> I have been working on the basis that a(0)=2 because the nearest prime to 0
> is 2 and so is 2 away.
> Likewise, a(prime)=0.
> 
> So... why is the 14th digit in the above sequence, which should be a(13),
> not equal to 0? And shouldn't a(15)=2?