|
| |
|
|
A139814
|
|
a(n)=a(n-1)+a(n-2)+a(n-3)+2a(n-4); a(0)=0,a(1)=1,a(2)=3,a(3)=7.
|
|
1
|
|
|
|
0, 1, 3, 7, 11, 23, 47, 95, 187, 375, 751, 1503, 3003, 6007, 12015, 24031, 48059, 96119, 192239, 384479, 768955, 1537911, 3075823, 6151647, 12303291, 24606583, 49213167, 98426335, 196852667, 393705335, 787410671, 1574821343, 3149642683
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,3
|
|
|
LINKS
|
Table of n, a(n) for n=0..32.
Index to sequences with linear recurrences with constant coefficients, signature (1,1,1,2).
|
|
|
FORMULA
|
O.g.f.: -x(1+2x+3x^2)/((2x-1)(1+x)(x^2+1)). a(n) = (-1)^(n+1)/3 +11*2^n/15 -2*(-1)^[n/2]*A000034(n)/5 . - R. J. Mathar, May 24 2008
a(n)=(2/5+1/5*I)*I^n+(1/3)*(-1)^n+(11/30)*2^n+(2/5-1/5*I)*(-I)^n, with n>=1 and I=(-1)^(1/2) - Paolo P. Lava, Jun 03 2008
|
|
|
MATHEMATICA
|
LinearRecurrence[{1, 1, 1, 2}, {0, 1, 3, 7}, 35] (* From Harvey P. Dale, Apr 20 2011 *)
|
|
|
CROSSREFS
|
Cf. A132429.
Sequence in context: A139253 A116606 A188132 * A099902 A092284 A024459
Adjacent sequences: A139811 A139812 A139813 * A139815 A139816 A139817
|
|
|
KEYWORD
|
nonn,easy
|
|
|
AUTHOR
|
Paul Curtz, May 23 2008
|
|
|
EXTENSIONS
|
More terms from R. J. Mathar, May 24 2008
|
|
|
STATUS
|
approved
|
| |
|
|
