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

 

Logo

The OEIS is looking to hire part-time people to help edit core sequences, upload scanned documents, process citations, fix broken links, etc. - Neil Sloane, njasloane@gmail.com

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A122115 a(i)=a(i-1)+a(i-3)+a(i-5) 1
-3, -1, 4, 8, 15, 16, 23, 42, 66, 104, 162, 251, 397, 625, 980, 1539, 2415, 3792, 5956, 9351, 14682, 23053, 36196, 56834, 89238, 140116, 220003, 345437, 542387, 851628, 1337181, 2099571, 3296636, 5176204, 8127403, 12761220, 20036995, 31461034, 49398458, 77562856, 121785110, 191220563, 300244453 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..43.

Index entries for linear recurrences with constant coefficients, signature (1, 0, 1, 0, 1).

FORMULA

G.f.: x*(-3+2*x+5x^2+7*x^3+8*x^4)/(1-x-x^3-x^5). - Philippe Deléham, Oct 20 2006

EXAMPLE

-3+4+15= 16

-1+8+16= 23

4+15+23= 42

MAPLE

a[1]:=-3: a[2]:=-1: a[3]:=4: a[4]:=8: a[5]:=15: for n from 6 to 45 do a[n]:=a[n-1]+a[n-3]+a[n-5] od: seq(a[n], n=1..45); - Emeric Deutsch, Oct 23 2006

MATHEMATICA

LinearRecurrence[{1, 0, 1, 0, 1}, {-3, -1, 4, 8, 15}, 50] (* Harvey P. Dale, Apr 22 2013 *)

CROSSREFS

This sequence includes the "Lost" numbers, 4 8 15 16 23 42, A104101 [From Rick Powers (powersr(AT)westerntc.edu), Sep 18 2009]

Sequence in context: A050059 A025121 A025097 * A049916 A220605 A094166

Adjacent sequences:  A122112 A122113 A122114 * A122116 A122117 A122118

KEYWORD

sign

AUTHOR

Jian Tang (jian.tang(AT)gmail.com), Oct 19 2006

EXTENSIONS

More terms from Emeric Deutsch, Oct 23 2006

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy .

Last modified May 28 20:12 EDT 2017. Contains 287241 sequences.