1,2

Euler transform of length 2 sequence [ -4, 3].

a(n) is multiplicative with a(2^e) = -(4^e) if e>0, a(p^e) = (p^2)^e if p>2.

G.f.: x * (1 - x) / (1 + x)^3.

E.g.f.: exp(-x) * (x - x^2).

(PARI) {a(n) = -(-1)^n * n^2}

-(-1)^n A000290(n) = a(n).

Sequence in context: A162497 A069821 A000290 this_sequence A144913 A018885 A025741

Adjacent sequences: A162392 A162393 A162394 this_sequence A162396 A162397 A162398

sign,mult

Michael Somos, Jul 02 2009