OFFSET
1,2
EXAMPLE
a(3) = 5 because between the 3rd and 4th primitive practical numbers, namely 6 and 20 there are 5 primes. They are 7, 11, 13, 17 and 19.
MATHEMATICA
lst=Last/@ReadList["https://oeis.org/A267124/b267124.txt", {Number, Number}]; seq=Table[PrimePi[lst[[n+1]]]-PrimePi[lst[[n]]], {n, 1, Length@lst-1}]; seq[[1;; 100]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Frank M Jackson, Sep 22 2024
STATUS
approved