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

 

Logo

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A047381 Numbers that are congruent to {0, 1, 2, 4, 5} mod 7. 2
0, 1, 2, 4, 5, 7, 8, 9, 11, 12, 14, 15, 16, 18, 19, 21, 22, 23, 25, 26, 28, 29, 30, 32, 33, 35, 36, 37, 39, 40, 42, 43, 44, 46, 47, 49, 50, 51, 53, 54, 56, 57, 58, 60, 61, 63, 64, 65, 67, 68, 70, 71, 72, 74, 75, 77, 78 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Index to sequences with linear recurrences with constant coefficients, signature (1,0,0,0,1,-1)

FORMULA

a(n)= floor( (7/5)(n-1) ). [Gary Detlefs, Feb 20 2010]

a(n)= +a(n-1) +a(n-5) -a(n-6). G.f. x^2*(1+x+2*x^2+x^3+2*x^4) / ( (x^4+x^3+x^2+x+1)*(x-1)^2 ). - R. J. Mathar, Mar 11 2011

MAPLE

seq(floor((7/5)*(n-1)), n=1..56); [Gary Detlefs, Feb 20 2010]

MATHEMATICA

CoefficientList[Series[x (1 + x + 2 x^2 + x^3 + 2 x^4) / ((x^4 + x^3 + x^2 + x + 1) (x - 1)^2), {x, 0, 60}], x] (* Vincenzo Librandi, Jul 26 2013 *)

PROG

(MAGMA) [ n: n in [1..80] | n mod 7 in [0, 1, 2, 4, 5] ]; // Vincenzo Librandi, Jul 26 2013

CROSSREFS

Sequence in context: A014132 A184008 A183862 * A097506 A189794 A001951

Adjacent sequences:  A047378 A047379 A047380 * A047382 A047383 A047384

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Formula and Maple code adapted to the offset. [Wesley Ivan Hurt, Jul 16 2013]

STATUS

approved

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

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

Last modified December 20 16:24 EST 2014. Contains 252269 sequences.