login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A122299 Expansion of -x*(-1+x) / ( 1-2*x-3*x^2+x^3 ). 0
0, 1, 1, 5, 12, 38, 107, 316, 915, 2671, 7771, 22640, 65922, 191993, 559112, 1628281, 4741905, 13809541, 40216516, 117119750, 341079507, 993301748, 2892722267, 8424270271, 24533405595, 71446899736, 208069745986, 605946785585 (list; graph; refs; listen; history; internal format)
OFFSET

1,4

COMMENTS

Lower right entry of the n-th power of the 5x5 matrix shown in the Mathematica program.

LINKS

Index to sequences with linear recurrences with constant coefficients, signature (2,3,-1)

FORMULA

a(n)= +2*a(n-1) +3*a(n-2) -a(n-3).

MATHEMATICA

M = {{1, 1, 1, 1, 1}, {1, 0, 0, 1, 0}, {1, 0, 1, 0, 0}, {1, 1, 0, 0, 0}, {1, 0, 0, 0, 0}}; v[1] = {0, 0, 0, 0, 1}; v[n_] := v[n] = M.v[n - 1]; a1 = Table[v[n][[1]], {n, 1, 50}]

CROSSREFS

Sequence in context: A077918 A034752 A095310 * A162269 A028322 A169588

Adjacent sequences:  A122296 A122297 A122298 * A122300 A122301 A122302

KEYWORD

nonn

AUTHOR

Gary Adamson and Roger Bagula (qntmpkt(AT)yahoo.com), Oct 19 2006

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 14 18:47 EST 2012. Contains 205663 sequences.