Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A006138
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A006138 a(n)=a(n-1)+3a(n-2).
(Formerly M1399)
+0
4
1, 2, 5, 11, 26, 59, 137, 314, 725, 1667, 3842, 8843, 20369, 46898, 108005, 248699, 572714, 1318811, 3036953, 6993386, 16104245, 37084403, 85397138, 196650347, 452841761 (list; graph; listen)
OFFSET

0,2

COMMENT

The binomial transform of a(n) is b(n)=A006190(n+1), which satisfies b(n)=3b(n-1)+b(n-2). - Paul Barry (pbarry(AT)wit.ie), May 21 2006

Partial sums of A105476. - Paul Barry (pbarry(AT)wit.ie), Feb 02 2007

REFERENCES

N. T. Gridgeman, A new look at Fibonacci generalization, Fib,. Quart., 11 (1973), 40-55.

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.

FORMULA

a(n)=Sum_{k, 0<=k<=n+1}A122950(n+1,k)*2^(n+1-k) . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jan 04 2008

G.f.: (1+x)/(1-x-3x^2); - Paul Barry (pbarry(AT)wit.ie), May 21 2006

a(n)=sum{k=0..n, C(floor((2n-k)/2),n-k)*3^floor(k/2)} - Paul Barry (pbarry(AT)wit.ie), Feb 02 2007

MAPLE

A006138:=-(1+z)/(-1+z+3*z**2); [S. Plouffe in his 1992 dissertation.]

CROSSREFS

Sequence in context: A005469 A026787 A064416 this_sequence A124217 A095981 A082397

Adjacent sequences: A006135 A006136 A006137 this_sequence A006139 A006140 A006141

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 July 25 07:41 EDT 2008. Contains 142293 sequences.


AT&T Labs Research