A321506 Numbers m such that m and m+1 each have at least 6 distinct prime factors.

11243154, 13516580, 16473170, 16701684, 17348330, 19286805, 20333495, 21271964, 21849905, 22054515, 22527141, 22754589, 22875489, 24031370, 25348070, 25774329, 28098245, 28618394, 28625960, 30259229, 31846269, 32642805, 32734910, 33205029, 33631520, 33641894, 35023365

Offset: 1

Author

M. F. Hasler, Nov 12 2018

Keywords

• nonn

Comments

Equals A273879 up to a(138) = 58524465, which is not in A273879: see A321496 for the complement.

Links

• M. F. Hasler, Table of n, a(n) for n = 1..150

Crossrefs

Cf. A273879 (variant with "exactly 6"), A321496 (terms not in A273879).

Cf. A321505 (analog for k=5 prime factors).

Programs

Mathematica

Select[Range[36000000], PrimeNu[#] > 5 && PrimeNu[# + 1] > 5 &] (* Amiram Eldar, Nov 12 2018 *)
Position[Partition[PrimeNu[Range[3503*10^4]],2,1],?(#[[1]]>5&&#[[2]]> 5&), 1,Heads-> False]//Flatten (* _Harvey P. Dale, Jul 28 2020 *)

PARI

is(n)=omega(n)>=6&&omega(n+1)>=6