OFFSET
1,1
FORMULA
EXAMPLE
a(1) = 2*(-1)^1 = -2.
a(2) = 3*(-1)^2 = 3.
a(3) = 5*(-1)^3 = -5.
MATHEMATICA
Table[Prime[n]*(-1)^n, {n, 1, 70}]
Table[If[OddQ[n], -Prime[n], Prime[n]], {n, 70}] (* Harvey P. Dale, Jul 01 2016 *)
PROG
(PARI) a(n) = prime(n)*(-1)^n \\ Felix Fröhlich, Jun 15 2016
CROSSREFS
KEYWORD
sign
AUTHOR
Terry D. Grant, Jun 12 2016
STATUS
approved