20190205, 12:15  #1 
Jun 2003
Suva, Fiji
7F8_{16} Posts 
Rough number behaviour close to record gaps
I have investigated rough number behaviour close to the first instance prime gaps from 100 to 1380 to see whether any of the first instance gaps were close to nearby regions of high incidence of smooth numbers (or its converse: low incidence of rough numbers).
For this post I have constructed a graph which is based on looking at the incidence of 41rough numbers in ranges close to where the first instance prime gaps are. A 41rough number is a number where all prime factors are >41. a worked example: Take the first instance gap of length 1380 with the lower prime p(1) 1031501833130243273. The integer range between the lower and upper prime p(2) contains g=193 41rough integers. I looked at n ranges of 1380 integers, commencing at p(1)+1, p(1)+2...p(1)+n and determined the numbers x of 41rough integers, x(n1),x(n2).... in each range. I then determined the largest count x(max) and smallest count x(min) of 41rough integers in the n ranges. The expected number E of 41rough integers in an integer range of 1380 is 14.50937% of 1380 = 200.223 For n = 1e6, I found x(max) and x(min) were 216 and 187 I plotted the differences between the g and E, x(max) and E and x(min) and E and express these differences as a ratio compared to E The resulting graph shows that, although g is normally lower than E, this is not always the case, and rarely does g come anywhere close to x(min). In the graph:.
x(min) approximates to the idea of using offsets to primorials P# which seek to find regions where there are very small numbers of Prough numbers, hence many offset records are in integer regions where the count of rough numbers are close to and perhaps even exceed x(min) 
20190207, 16:41  #2 
May 2018
281 Posts 
That is very cool. Another thing is if there are big clusters of primes near record prime gaps. For example, the prime nonuplet 1277, 1279, 1283, 1289, 1291, 1297, 1301, 1303, 1307 is near the record prime gap from 1327 to 1361.

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