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A335496 a(n) is the least odd number k such that Omega(k) = n, Omega(k+2) = n+1, and Omega(k+4) = n+2, where Omega(k) is the number of prime factors of k (A001222). 1
23, 871, 5423, 229955, 13771373, 558588875, 21549990623, 1325878234371 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(n) (mod 81) for n=1..8: {23, 61, 77, 77, 77, 77, 77, 0}.

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

23 (prime), 25=5*5 (semiprime),27=3*3*3 (3-almost prime);

871 = 13*67 (semiprime),

873 = 3*3*97 (3-almost prime),

875 = 5*5*5*7 (4-almost prime).

CROSSREFS

Sequence in context: A158505 A217116 A081731 * A183523 A233339 A008961

Adjacent sequences:  A335493 A335494 A335495 * A335497 A335498 A335499

KEYWORD

nonn,more

AUTHOR

Zak Seidov and Giovanni Resta, Jun 11 2020

STATUS

approved

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Last modified September 30 12:21 EDT 2020. Contains 337439 sequences. (Running on oeis4.)