%I
%S 1376,6656,9424,12104,18656,19376,29224,30304,40976,41504,41824,44864,
%T 51624,57784,59224,61984,66520,70300,70624,70736,72064,74920,82160,
%U 87296,93500,94424
%N 3apexes of Omega: n such that Omega(n3) < Omega(n2)< Omega(n1) < Omega(n) > Omega(n+1) > Omega(n+2) > Omega(n+3), where Omega(m) = the number of prime factors of m, counting multiplicity.
%C I call n a "kapex" (or "apex of height k") of the arithmetical function f if n satisfies f(nk) < ... < f(n1) < f(n) > f(n+1) > .... > f(n+k).
%e Omega(1373) = 1 < Omega(1374) = 3 < Omega(1375) = 4 < Omega(1376)= 6 > Omega(1377) = 5 > Omega(1378) = 3 > Omega(1379) = 2, so 1376 is a 3apex of Omega.
%t Omega[n_] := Apply[Plus, Transpose[FactorInteger[n]][[2]]]; Select[Range[5, 10^5], Omega[ #  3] < Omega[ #  2] < Omega[ #  1] < Omega[ # ] > Omega[ # + 1] > Omega[ # + 2] > Omega[ # + 3] &]
%Y Cf. A001222.
%K nonn
%O 1,1
%A _Joseph L. Pe_, Nov 13 2002
