|
Search: id:A116201
|
|
|
| A116201 |
|
a(n) = a(n-1) + a(n-2) + a(n-3) - a(n-4). |
|
+0
2
|
|
| 0, 1, 1, 1, 3, 4, 7, 13, 21, 37, 64, 109, 189, 325, 559, 964, 1659, 2857, 4921, 8473, 14592, 25129, 43273, 74521, 128331, 220996, 380575, 655381, 1128621, 1943581, 3347008, 5763829, 9925797, 17093053, 29435671, 50690692, 87293619, 150326929
(list; graph; listen)
|
|
|
OFFSET
|
0,5
|
|
|
COMMENT
|
G.f.: (-x^3 + x)/(x^4 - x^3 - x^2 - x + 1) - Alexander R. Povolotsky (pevnev(AT)juno.com), Apr 01 2008
|
|
FORMULA
|
O.g.f: -x*(x-1)*(x+1)/(1-x-x^2-x^3+x^4). a(n)=A135431(n)-A135431(n-1). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 31 2008
|
|
MAPLE
|
a[0]:=0: a[1]:=1: a[2]:=1: a[3]:=1: for n from 4 to 35 do a[n]:= a[n-1]+a[n-2]+a[n-3]-a[n-4] end do: seq(a[n], n=0..35); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Apr 12 2008
|
|
MATHEMATICA
|
a = {0, 1, 1, 1, 3}; Do[AppendTo[a, a[[ -1]]+a[[ -2]]+a[[ -3]]-a[[ -4]]], {80}]; a - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Mar 24 2008
|
|
CROSSREFS
|
Cf. A116732.
Sequence in context: A089374 A029552 A125118 this_sequence A092406 A121174 A050071
Adjacent sequences: A116198 A116199 A116200 this_sequence A116202 A116203 A116204
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
Richard Guy (rkg(AT)cpsc.ucalgary.ca), Mar 23 2008
|
|
EXTENSIONS
|
More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl) and Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Mar 31 2008
|
|
|
Search completed in 0.002 seconds
|
