OFFSET
1,1
COMMENTS
The convention here is that only the lower member of a cousin prime pair be less than the selected bound 10^n.
Cousin primes, like twin primes, can be approximated by the Hardy-Littlewood formula for the number of twin primes < n. For example, the number of cousin primes < 10^12 = 1870585459 while Hardy-Littlewood gives 1870559867. The sum of cousin primes < 10^6 divided by 4 also approximates the number of cousin primes < 10^12 with 1844802199. These two methods are asymptotic to the true value as n -> infinity.
LINKS
Cino Hilliard, Gcc Sum Cousin primes [broken link]
FORMULA
A cousin prime pair is a pair of primes that differ by 4.
EXAMPLE
(3,7) and (7,11) are cousin primes < 10 since 7 < 10. So 2 is the first entry in the sequence.
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Cino Hilliard, Nov 22 2008
EXTENSIONS
a(13)-a(15) from Martin Ehrenstein, Sep 03 2021
STATUS
approved