a(n) = number of distinct prime divisors (taken together) of numbers of the form 2x^2+1 for x<=10^n.
A144851
a(n) = number of distinct prime divisors (taken together) of numbers of the form 2x^2+1 for x<=10^n.
Terms
- a(0) =8a(1) =76a(2) =760a(3) =7445a(4) =73477a(5) =726948a(6) =7218256a(7) =71801859a(8) =715087632a(9) =7127665635a(10) =71089166879a(11) =709344259821
External references
- oeis: A144851