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

1,1

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

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 *)

Prog

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

Crossrefs

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

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

Sequence in context: A219750 A201253 A273879 * A253960 A253967 A253763

Adjacent sequences: A321503 A321504 A321505 * A321507 A321508 A321509

Keyword

nonn

Author

M. F. Hasler, Nov 12 2018

Status

approved