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A082422
Numbers n such that P(n) > P(n+2) > P(n+1), where P(n) = largest prime factor of n (A006530).
9
7, 19, 23, 26, 31, 47, 53, 67, 74, 76, 83, 89, 97, 109, 113, 119, 124, 127, 131, 134, 139, 146, 159, 167, 174, 181, 183, 188, 199, 207, 211, 215, 219, 233, 244, 246, 251, 259, 263, 274, 287, 293, 303, 307, 314, 323, 327, 337, 339, 349, 353, 359, 362, 367, 379, 383, 386
OFFSET
1,1
REFERENCES
Antal Balog, On the largest prime factor of consecutive integers, Abstracts Amer. Math. Soc., 25 (No. 2, 2002), p. 337, #975-11-76.
LINKS
P. Erdős and C. Pomerance, On the largest prime factors of n and n+1, Aequationes Math. 17 (1978), p. 311-321. [alternate link]
MATHEMATICA
With[{lfs=Table[FactorInteger[n][[-1, 1]], {n, 400}]}, Flatten[ Position[ Partition[ lfs, 3, 1], _?(#[[1]]>#[[3]]>#[[2]]&), {1}, Heads->False]]] (* Harvey P. Dale, Sep 25 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 25 2003
STATUS
approved