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A047282 Numbers that are congruent to {1, 3, 6} mod 7. 2
1, 3, 6, 8, 10, 13, 15, 17, 20, 22, 24, 27, 29, 31, 34, 36, 38, 41, 43, 45, 48, 50, 52, 55, 57, 59, 62, 64, 66, 69, 71, 73, 76, 78, 80, 83, 85, 87, 90, 92, 94, 97, 99, 101, 104, 106, 108, 111, 113, 115, 118, 120, 122, 125, 127, 129, 132, 134, 136, 139, 141 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..61.

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

FORMULA

G.f.: x*(1+2*x+3*x^2+x^3)/((1+x+x^2)*(x-1)^2). - R. J. Mathar, Oct 25 2011

From Wesley Ivan Hurt, Jun 10 2016: (Start)

a(n) = a(n-1) + a(n-3) - a(n-4) for n>4.

a(n) = (21*n-12+3*cos(2*n*Pi/3)+sqrt(3)*sin(2*n*Pi/3))/9.

a(3*k) = 7*k-1, a(3*k-1) = 7*k-4, a(3*k-2) = 7*k-6. (End)

a(n) = 2*n - 1 + floor(n/3). - Wesley Ivan Hurt, Dec 28 2016

MAPLE

A047282:=n->(21*n-12+3*cos(2*n*Pi/3)+sqrt(3)*sin(2*n*Pi/3))/9: seq(A047282(n), n=1..100); # Wesley Ivan Hurt, Jun 10 2016

MATHEMATICA

Select[Range[0, 150], MemberQ[{1, 3, 6}, Mod[#, 7]] &] (* Wesley Ivan Hurt, Jun 10 2016 *)

PROG

(MAGMA) [n : n in [0..150] | n mod 7 in [1, 3, 6]]; // Wesley Ivan Hurt, Jun 10 2016

CROSSREFS

Sequence in context: A189471 A169863 A304500 * A304497 A189937 A190325

Adjacent sequences:  A047279 A047280 A047281 * A047283 A047284 A047285

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified October 21 22:47 EDT 2019. Contains 328315 sequences. (Running on oeis4.)