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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A047287 Numbers that are congruent to {0, 1, 2, 3, 6} mod 7. 1
0, 1, 2, 3, 6, 7, 8, 9, 10, 13, 14, 15, 16, 17, 20, 21, 22, 23, 24, 27, 28, 29, 30, 31, 34, 35, 36, 37, 38, 41, 42, 43, 44, 45, 48, 49, 50, 51, 52, 55, 56, 57, 58, 59, 62, 63, 64, 65, 66, 69, 70, 71, 72, 73, 76, 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 entries for linear recurrences with constant coefficients, signature (1,0,0,0,1,-1).

FORMULA

G.f.: x^2*(1+x+x^2+3*x^3+x^4)/((1-x)^2*(1+x+x^2+x^3+x^4)). [Colin Barker, May 14 2012]

a(n) = a(n-1) + a(n-5) - a(n-6) for n > 6. Vincenzo Librandi, May 15 2012

a(n) = (7n - 5 - 2*(n mod 5)/5. - Wesley Ivan Hurt, Dec 28 2016

MATHEMATICA

Select[Range[0, 400], MemberQ[{0, 1, 2, 3, 6}, Mod[#, 7]]&] (* Vincenzo Librandi, May 15 2012 *)

PROG

(MAGMA) I:=[0, 1, 2, 3, 6, 7]; [n le 6 select I[n] else Self(n-1)+Self(n-5)-Self(n-6): n in [1..70]]; // Vincenzo Librandi, May 15 2012

CROSSREFS

Sequence in context: A265334 A050019 A163099 * A039047 A047246 A039029

Adjacent sequences:  A047284 A047285 A047286 * A047288 A047289 A047290

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 12 07:03 EST 2019. Contains 329052 sequences. (Running on oeis4.)