[seqfan] Re: Smallest prime with a substring of exactly n zeros

[Hans Havermann]

A small quibble over the notion that a={1..9}, b={1,3,7,9} creates 36 candidate primes. The sum of the two or three non-zero digits in these primes can't be a multiple of three, so the list 'a' is materially reduced (by three), thus creating only 24 candidate primes.

> On Feb 20, 2016, at 5:42 PM, Bob Selcoe <rselcoe at entouchonline.net> wrote:
> 
> I've posted some observations on https://oeis.org/A037053 to flesh out the ideas, publication pending.  Hopefully all is clear and I've made no calculation errors.