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A195086 Numbers k such that (number of prime factors of k counted with multiplicity) less (number of distinct prime factors of k) = 2. 14
8, 24, 27, 36, 40, 54, 56, 88, 100, 104, 120, 125, 135, 136, 152, 168, 180, 184, 189, 196, 225, 232, 248, 250, 252, 264, 270, 280, 296, 297, 300, 312, 328, 343, 344, 351, 375, 376, 378, 396, 408, 424, 440, 441, 450, 456, 459, 468, 472, 484, 488 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A001222(a(n)) - A001221(a(n)) = 2.

A046660(a(n)) = 2. - Reinhard Zumkeller, Nov 29 2015

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Index entries for sequences computed from exponents in factorization of n

MAPLE

op(select(n->bigomega(n)-nops(factorset(n))=2, [$1..488])); # Paolo P. Lava, Jul 03 2018

MATHEMATICA

Select[Range[500], PrimeOmega[#]-PrimeNu[#]==2&]

PROG

(PARI) is(n)=bigomega(n)-omega(n)==2 \\ Charles R Greathouse IV, Sep 14 2015

(PARI) is(n)=my(f=factor(n)[, 2]); vecsum(f)==#f+2 \\ Charles R Greathouse IV, Aug 01 2016

(Haskell)

a195086 n = a195086_list !! (n-1)

a195086_list = filter ((== 2) . a046660) [1..]

-- Reinhard Zumkeller, Nov 29 2015

CROSSREFS

Subsequence of A048108.

Subsequences: A030078 and A085986.

Cf. A001221, A001222, A025487, A060687, A195069, A195087, A195088, A195089, A195090, A195091, A195092, A195093, A046660, A257851, A261256, A264959.

Sequence in context: A295661 A240111 A301517 * A336593 A176297 A175496

Adjacent sequences:  A195083 A195084 A195085 * A195087 A195088 A195089

KEYWORD

nonn

AUTHOR

Harvey P. Dale, Sep 08 2011

STATUS

approved

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Last modified September 30 21:27 EDT 2020. Contains 337440 sequences. (Running on oeis4.)