|
Search: id:A061019
|
|
|
| A061019 |
|
Negate primes in factorization of n. |
|
+0
3
|
|
| 1, -2, -3, 4, -5, 6, -7, -8, 9, 10, -11, -12, -13, 14, 15, 16, -17, -18, -19, -20, 21, 22, -23, 24, 25, 26, -27, -28, -29, -30, -31, -32, 33, 34, 35, 36, -37, 38, 39, 40, -41, -42, -43, -44, -45, 46, -47, -48, 49, -50, 51, -52, -53, 54, 55, 56, 57, 58, -59, 60, -61, 62, -63, 64, 65, -66, -67, -68, 69, -70
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
Inverse Moebius transform of A001615.
n*lambda(n), where lambda is Liouville's function: A008836.
Totally multiplicative sequence with a(p) = -p for prime p. [From Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), Nov 01 2009]
|
|
FORMULA
|
Multiplicative with a(p) = -p, p prime.
a(n)= (-1)^(number of primes dividing n)*n = n * (-1)^A001222(n).
|
|
EXAMPLE
|
a(6)=(-2)(-3) = +6, while a(8)=(-2)^3 = -8.
|
|
CROSSREFS
|
Cf. A000027, A001222, A061020, A001615.
Sequence in context: A105811 A069782 A088480 this_sequence A028310 A097045 A118759
Adjacent sequences: A061016 A061017 A061018 this_sequence A061020 A061021 A061022
|
|
KEYWORD
|
easy,nice,sign,mult,new
|
|
AUTHOR
|
Marc LeBrun (mlb(AT)well.com), Apr 13 2001
|
|
|
Search completed in 0.002 seconds
|
