A076764 n such that Omega(n-1) < Omega(n) < Omega(n+1), where Omega(m) = the number of prime factors of m, counting multiplicity.

62, 63, 74, 188, 194, 195, 207, 242, 255, 275, 278, 279, 314, 363, 374, 398, 399, 404, 422, 423, 455, 458, 483, 494, 495, 524, 539, 614, 615, 662, 663, 674, 692, 728, 734, 735, 747, 758, 759, 764, 782, 783, 854, 867, 890, 927, 935, 975, 998, 999

Offset: 1

Author

Joseph L. Pe, Nov 13 2002

Keywords

• nonn

Examples

			Omega(61) = 1 < Omega(62) = 2 < Omega(63) = 3, so 62 is a 1-apex of Omega.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A001222, A097619.

Programs

Maple

Res:= NULL: a:= numtheory:-bigomega(1): b:= numtheory:-bigomega(2):
for n from 3 to 1001 do
  c:= numtheory:-bigomega(n);
  if a < b and b < c then Res:= Res, n-1 fi;
  a:= b; b:= c;
od:
Res; # Robert Israel, Oct 28 2018

Mathematica

Select[Range[3, 10^3], Omega[ # - 1] < Omega[ # ] < Omega[ # + 1] &]
Flatten[Position[Partition[PrimeOmega[Range[1000]],3,1],?(Min[ Differences[ #]]>0&),{1},Heads->False]]+1 (* _Harvey P. Dale, Nov 28 2015 *)

Extensions

Edited by Robert Israel, Oct 28 2018