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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

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Last modified September 17 01:33 EDT 2014. Contains 246831 sequences.