OFFSET
1,3
LINKS
Robert G. Wilson v, Table of n, a(n) for n = 1..75
EXAMPLE
The 5th largest prime gap (after 2-3, 3-5, 7-11 and 23-29) occurs between 89 and 97, and there are 6 primes which occur exactly once in this gap, namely 7 (dividing 91), 13 (dividing 91), 19 (dividing 95), 23 (dividing 92), 31 (dividing 93) and 47 (dividing 94), so a(5)=6.
MATHEMATICA
gp = (* the list of primes in A002386 *); f[n_] := Block[{p = gp[[n]], q = NextPrime[ gp[[n]]]}, r = Range[p + 1, q - 1]; lng = Length@ r; t = Split@ Sort@ Flatten@ Table[ First@# & /@ FactorInteger[ r[[i]]], {i, lng}]; Length@ Select[t, Length@# == 1 &]]; Array[f, 75] (* Robert G. Wilson v, Jan 23 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Mamuka Jibladze, Jan 23 2015
EXTENSIONS
a(43)-a(57) from Robert G. Wilson v, Jan 23 2015
STATUS
approved