

A122444


Greatest prime factor of powers of semiprimes.


2



1, 2, 3, 3, 5, 7, 5, 2, 7, 11, 5, 13, 11, 17, 7, 3, 19, 13, 23, 7, 17, 11, 19, 29, 31, 2, 13, 23, 37, 11, 3, 41, 17, 43, 29, 13, 31, 47, 19, 5, 53, 37, 23, 59, 17, 11, 61, 41, 43, 19, 67, 47, 71, 13, 29, 73, 31, 79, 53, 23, 83
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OFFSET

1,2


COMMENTS

A122443 is least prime factor of powers of semiprimes. Cf. A076397 Largest prime factor of nth perfect power.


LINKS



FORMULA



MATHEMATICA

FactorInteger[#][[1, 1]] & /@ Select[Range@ 168, Function[n, Or[n == 1, And[Length@ # == 1, EvenQ@ First@ #], And[Length@ # == 2, SameQ @@ #]] &[FactorInteger[n][[All, 1]]]]] (* Michael De Vlieger, Mar 04 2017 *)


CROSSREFS



KEYWORD

easy,nonn


AUTHOR



STATUS

approved



