OFFSET
5,1
FORMULA
pi(n*a(n)) = a(n) + n.
EXAMPLE
pi(5*9) = 9 + 5.
pi(6*7) = 7 + 6.
pi(7*6) = 6 + 7.
pi(8*998) = 998 + 8.
pi(9*5) = 5 + 9.
...
pi(15*636787) = 636787 + 15.
pi(16*1617099) = 1617099 + 16.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Seiichi Manyama, Jan 17 2017
EXTENSIONS
a(19)-a(28) from Chai Wah Wu, May 03 2018
a(29)-a(30) from Chai Wah Wu, May 08 2018
STATUS
approved