|
%I #10 Jan 10 2016 11:42:31
%S 3,5,7,11,15,17,19,23,26,29,31,35,39,41,44,47,49,51,53,55,59,63,65,67,
%T 69,71,74,76,80,83,87,89,95,97,99,101,104,107,109,111,113,116,119,124,
%U 127,129,131,134,137,139,143,146,149,153,155,159,161,164,167,174,179,181,183
%N Numbers n such that P(n) > P(n+1) < P(n+2), where P(n) = largest prime factor of n (A006530).
%D Antal Balog, On the largest prime factor of consecutive integers, Abstracts Amer. Math. Soc., 25 (No. 2, 2002), p. 337, #975-11-76.
%H T. D. Noe, <a href="/A082418/b082418.txt">Table of n, a(n) for n = 1..1000</a>
%H P. Erdős and C. Pomerance, <a href="http://www.math.dartmouth.edu/~carlp/PDF/paper17.pdf">On the largest prime factors of n and n+1</a>, Aequationes Math. 17 (1978), p. 311-321. [<a href="http://www.renyi.hu/~p_erdos/1978-29.pdf">alternate link</a>]
%F a(n) = A100390(n) - 1. - T. D. Noe, Nov 26 2007
%t Flatten[Position[Partition[Table[FactorInteger[n][[-1,1]],{n,200}],3,1], _?(#[[1]]> #[[2]] <#[[3]]&),{1},Heads->False]] (* _Harvey P. Dale_, Jan 10 2016 *)
%Y Cf. A006530, A082417-A082422, A071869, A071870.
%K nonn
%O 1,1
%A _N. J. A. Sloane_, Apr 25 2003
|
