a(n) = number of distinct prime divisors (taken together) of numbers of the form 4x^2+1 for x<=10^n.
A144852
a(n) = number of distinct prime divisors (taken together) of numbers of the form 4x^2+1 for x<=10^n.
Terms
- a(0) =9a(1) =87a(2) =836a(3) =8000a(4) =78124a(5) =766585a(6) =7556731a(7) =74771106a(8) =741554656a(9) =7366252759a(10) =73261462211a(11) =729280694469
External references
- oeis: A144852