A076153 Numbers n such that Omega(n) = Omega(n-1)^2, where Omega(m) (A001222) denotes the number of prime factors of m, counted with multiplicity.

3, 16, 36, 40, 56, 88, 135, 156, 184, 204, 210, 220, 248, 250, 260, 296, 306, 315, 328, 330, 340, 342, 372, 414, 459, 472, 490, 516, 536, 546, 580, 584, 636, 650, 686, 690, 708, 714, 732, 735, 738, 804, 808, 819, 836, 850, 852, 870, 872, 940, 950, 966, 975, 996, 999

Offset: 1

Author

Joseph L. Pe, Oct 31 2002

Keywords

• easy
• nonn

Examples

			Omega(996) = 2^2 = Omega(995)^2, so 996 is a term of the sequence.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Similar to A109287; after a(1)=3 next difference is a(101)=1792 whereas A109287(100)=1794. - Ray Chandler, Mar 20 2007

Cf. A001222.

Programs

Mathematica

Select[Range[1000],PrimeOmega[#]==PrimeOmega[#-1]^2&] (* Ray Chandler, Jul 07 2015 *)
Flatten[Position[Partition[PrimeOmega[Range[1000]],2,1],?(#[[1]]^2==#[[2]]&),1,Heads-> False]]+ 1 (* _Harvey P. Dale, Nov 05 2023 *)

Extensions

Edited by Ray Chandler, Mar 20 2007