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A368780
Cubefree numbers divisible by the square of their largest prime factor.
1
4, 9, 18, 25, 36, 49, 50, 75, 98, 100, 121, 147, 150, 169, 196, 225, 242, 245, 289, 294, 300, 338, 361, 363, 441, 450, 484, 490, 507, 529, 578, 588, 605, 676, 722, 726, 735, 841, 845, 847, 867, 882, 900, 961, 980, 1014, 1058, 1083, 1089, 1156, 1183, 1210, 1225
OFFSET
1,1
LINKS
Rafael Jakimczuk, Some observations on the greatest prime factor of an integer, Annales Mathematicae Silesianae, Vol. 37, No. 1 (2023), pp. 67-81. See Theorem 2.2, p. 71.
MATHEMATICA
Select[Range[1500], Max[e = FactorInteger[#][[;; , 2]]] < 3 && e[[-1]] == 2 &]
PROG
(PARI) is(n) = {my(e = factor(n)[, 2]); n > 1 && vecmax(e) < 3 && e[#e] == 2; }
CROSSREFS
Intersection of A070003 and A004709 or A067259.
Cf. A006530.
Sequence in context: A313358 A263351 A064599 * A062952 A344405 A229027
KEYWORD
nonn,easy
AUTHOR
Amiram Eldar, Jan 05 2024
STATUS
approved