Dear seqfans, a is positive odd and A179382((a+1)/2)=(a-1)/(2^c),for some c>0 ,if a isnt prime,then a named "Mike Number". The 5 known Mike numbers searched by Peter Košinár is: 9, 92673, 143713, 4110529, 28688897 So what's the next or below 28688897 not found Mike Number looks like is very interesting. Yours Mike,