OFFSET
1,3
COMMENTS
Union of multiples of 4 and odd numbers with an even number of prime factors with multiplicity. - Charlie Neder, Feb 25 2019
After two initial terms (0 and 1), numbers n such that A086134(n) = 2. - Antti Karttunen, Sep 30 2019
A multiplicative semigroup; if m and n are in the sequence then so is m*n. (See also comments in A359780.) - Antti Karttunen, Jan 17 2023
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
MATHEMATICA
Select[Range[0, 133], EvenQ@ If[Abs@ # < 2, 0, # Total[#2/#1 & @@@ FactorInteger[Abs@ #]]] &] (* Michael De Vlieger, Sep 30 2019 *)
PROG
(Haskell)
a235992 n = a235992_list !! (n-1)
a235992_list = filter (even . a003415) [0..]
(Python)
from itertools import count, islice
from sympy import factorint
def A235992_gen(startvalue=0): # generator of terms >= startvalue
return filter(lambda n: not n&3 or (n&1 and not sum(factorint(n).values())&1), count(max(startvalue, 0)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Mar 11 2014
STATUS
approved