|
| |
|
|
A005120
|
|
a(n+6) = -3a(n+5)-5a(n+4)-5a(n+3)-5a(n+2)-3a(n+1)-a(n).
(Formerly M3770)
|
|
0
| |
|
|
0, 1, -1, 1, -1, -1, 5, -8, 7, 1, -19, 43, -55, 27, 64, -211, 343, -307, -85, 911, -1919, 2344, -989, -3151, 9625, -15049, 12609, 5671, -42496, 85609, -100225, 33977, 154007, -437009, 657901, -513512, -335665, 1974097, -3808891, 4265379
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,7
|
|
|
COMMENTS
| This is a divisibility sequence. If d divides n then a(d) divides a(n).
|
|
|
REFERENCES
| M. Duboue, Une suite recurrente remarquable, Europ. J. Combin., 4 (1983), 205-214.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
H. C. Williams, Edouard Lucas and Primality Testing, Wiley, 1998, p. 455. Math. Rev. 2000b:11139
|
|
|
LINKS
| Index to divisibility sequences
Index to sequences with linear recurrences with constant coefficients, signature (-3,-5,-5,-5,-3,-1).
|
|
|
FORMULA
| G.f.: x(1+2x+3x^2+2x^3+x^4)/(1+3x+5x^2+5x^3+5x^4+3x^5+x^6).
|
|
|
PROG
| (PARI) a(n)=polcoeff(x*(1+2*(x+x^3)+3*x^2+x^4)/(1+3*(x+x^5)+5*(x^2+x^3+x^4)+x^6)+x*O(x^n), n)
|
|
|
CROSSREFS
| Cf. A001608.
Sequence in context: A145432 A070371 A199444 * A133731 A021067 A047914
Adjacent sequences: A005117 A005118 A005119 * A005121 A005122 A005123
|
|
|
KEYWORD
| sign,easy
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
|
|
EXTENSIONS
| Edited by Michael Somos, Aug 02, 2002
|
| |
|
|
