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A321505 Numbers k such that k and k+1 each have at least 5 distinct prime factors. 6
254540, 310155, 378014, 421134, 432795, 483405, 486590, 486794, 488565, 489345, 507129, 522444, 545258, 549185, 558789, 558830, 567644, 577940, 584154, 591260, 598689, 627095, 634809, 637329, 663585, 666995, 667029, 678755, 687939, 690234, 707420, 712425, 720005, 720290, 728364, 743589 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Equals A140079 up to a(34) but a(35) = 728364 is not in A140079, see A321495.

LINKS

M. F. Hasler, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[Range[750000], PrimeNu[#] > 4 && PrimeNu[# + 1] > 4 &] (* Amiram Eldar, Nov 12 2018 *)

PROG

(PARI) is(n)=omega(n)>=5&&omega(n+1)>=5

CROSSREFS

Cf. A140079 (variant with "exactly 5"), A321495 (terms not in A140079).

Cf. A321504 (analog for k=4 prime factors), A321506 (analog for k=6).

Sequence in context: A069176 A253725 A140079 * A034631 A168352 A147579

Adjacent sequences:  A321502 A321503 A321504 * A321506 A321507 A321508

KEYWORD

nonn

AUTHOR

M. F. Hasler, Nov 12 2018

STATUS

approved

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Last modified June 4 07:43 EDT 2020. Contains 334822 sequences. (Running on oeis4.)