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A271909 Numbers k such that k and 3*k+1 have the same number of prime divisors (including multiplicities). 2
2, 15, 35, 38, 39, 55, 62, 63, 82, 86, 87, 91, 105, 106, 111, 114, 115, 118, 119, 134, 142, 147, 155, 159, 178, 187, 189, 194, 212, 218, 225, 226, 235, 238, 254, 258, 259, 267, 268, 275, 278, 282, 287, 295, 298, 299, 310, 314, 319, 326, 327, 334, 335, 338, 339, 343 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Numbers k such that bigomega(k) = bigomega(3*k+1).

MAPLE

with(numtheory): A271909:=n->`if`(bigomega(n)=bigomega(3*n+1), n, NULL): seq(A271909(n), n=1..800); # Wesley Ivan Hurt, Apr 22 2016

MATHEMATICA

Select[Range[350], PrimeOmega[#] == PrimeOmega[3 # + 1] &] (* Amiram Eldar, Apr 02 2020 *)

CROSSREFS

Cf. A001222, A272229.

Sequence in context: A300765 A300635 A301357 * A075541 A075542 A064113

Adjacent sequences:  A271906 A271907 A271908 * A271910 A271911 A271912

KEYWORD

nonn

AUTHOR

Benjamin Przybocki, Apr 22 2016

STATUS

approved

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Last modified September 21 21:32 EDT 2021. Contains 347605 sequences. (Running on oeis4.)