

A354567


a(n) is the least number k such that P(k)^n  k and P(k+1)^n  (k+1), where P(k) = A006530(k) is the largest prime dividing k, or 1 if no such k exists.


0




OFFSET

1,2


COMMENTS

a(1) = 1 since P(1) = 1 by convention. Without this convention we would have a(1) = 2.
a(5) <= 437489361912143559513287483711091603378 (De Koninck, 2009).


LINKS



EXAMPLE

a(2) = 8 since 8 = 2^3, P(8) = 2 and 2^28, 9 = 3^2, P(9) = 3 and 3^2  9, and 8 is the least number with this property.
a(3) = 6859 since 6859 = 19^3, P(6859) = 19 and 19^3  6859, 6860 = 2^2 * 5 * 7^3, P(6860) = 7 and 7^3  6860, and 6859 is the least number with this property.


CROSSREFS



KEYWORD

nonn,more,bref


AUTHOR



STATUS

approved



