A095915 - OEIS

A095915

Each number is twice times the product of the digits of the previous number.

1, 2, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16, 12, 4, 8, 16

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..85.

Index entries for linear recurrences with constant coefficients, signature (1, -1, 1).

FORMULA

From R. J. Mathar, Apr 13 2010:

a(n) = 2^(n-1) mod 20;

a(n) = a(n-1) - a(n-2) + a(n-3), n > 5.

G.f.: x*(3*x^2+5*x^3+10*x^4+x+1)/((1-x)*(1+x^2)).

PROG