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A122144
Numbers k such that q(k) = M(k) where q(n) is the largest prime divisor of k and M(k) is the largest prime power divisor of k.
4
2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 19, 20, 21, 22, 23, 26, 28, 29, 30, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 44, 46, 47, 51, 52, 53, 55, 57, 58, 59, 60, 61, 62, 65, 66, 67, 68, 69, 70, 71, 73, 74, 76, 77, 78, 79, 82, 83, 84, 85, 86, 87, 88, 89, 91, 92, 93, 94, 95, 97, 99
OFFSET
1,1
COMMENTS
Similar to A048839, the first difference occurs when n = 40.
LINKS
MATHEMATICA
Select[Range[2, 100], Max[Power @@@ (f = FactorInteger[#])] == f[[-1, 1]] &] (* Amiram Eldar, May 23 2024 *)
PROG
(PARI) isok(k) = {my(f = factor(k), pm = 0); if(k > 1, for(i = 1, #f~, pm = max(pm, f[i, 1]^f[i, 2])); pm == f[#f~, 1], 0); } \\ Amiram Eldar, May 23 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Douglas Stones (dssto1(AT)student.monash.edu.au), Aug 22 2006
EXTENSIONS
Edited by Ray Chandler, Aug 23 2006
STATUS
approved