0,3

a(n) = A007954(n) * (-1)^A055642(n).

Reinhard Zumkeller, Table of n, a(n) for n = 0..25000

a(289) = (-2) * (-8) * (-9) = -144;

a(2891) = (-2) * (-8) * (-9) * (-1) = 144.

(Haskell)

import Data.Char (digitToInt)

a187844 n = product $ map (negate . fromIntegral . digitToInt) $ show n

Cf. A187845 (partial sums).

Sequence in context: A031347 A087471 A128212 * A007954 A079475 A081286

Adjacent sequences: A187841 A187842 A187843 * A187845 A187846 A187847

sign,base,look

Reinhard Zumkeller, Mar 14 2011

approved