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

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

(Sage) [power_mod(2, n, 20)for n in range(0, 85)] # Zerinvary Lajos, Nov 03 2009

Crossrefs

Sequence in context: A020954 A070347 A342072 * A208278 A036120 A334629

Adjacent sequences: A095912 A095913 A095914 * A095916 A095917 A095918

Keyword

base,nonn

Author

Herman Jamke (hermanjamke(AT)fastmail.fm), Jul 13 2004

Status

approved