Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A001641
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A001641 A Fielder sequence.
(Formerly M2364 N0935)
+0
2
1, 3, 4, 11, 16, 30, 50, 91, 157, 278, 485, 854, 1496, 2628, 4609, 8091, 14196, 24915, 43720, 76726, 134642, 236283, 414645, 727654, 1276941, 2240878, 3932464, 6900996, 12110401, 21252275, 37295140, 65448411, 114853952, 201554638 (list; graph; listen)
OFFSET

1,2

REFERENCES

S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.

Fielder, Daniel C.; Special integer sequences controlled by three parameters. Fibonacci Quart 6 1968 64-70.

LINKS

S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.

S. Plouffe, 1031 Generating Functions and Conjectures, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.

Y. Puri and T. Ward, Arithmetic and growth of periodic orbits, J. Integer Seqs., Vol. 4 (2001), #01.2.1.

FORMULA

G.f.: x(1+2x+4x^3)/(1-x-x^2-x^4).

MAPLE

A001641:=-(1+2*z+4*z**3)/(z+1)/(z**3-z**2+2*z-1); [Conjectured by S. Plouffe in his 1992 dissertation.]

PROGRAM

(PARI) a(n)=if(n<0, 0, polcoeff(x*(1+2*x+4*x^3)/(1-x-x^2-x^4)+x*O(x^n), n))

CROSSREFS

Cf. A060945.

Adjacent sequences: A001638 A001639 A001640 this_sequence A001642 A001643 A001644

Sequence in context: A116654 A041020 A041527 this_sequence A007382 A127804 A027306

KEYWORD

nonn

AUTHOR

njas

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified October 13 20:18 EDT 2008. Contains 145016 sequences.


AT&T Labs Research