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A047379 Numbers that are congruent to {0, 2, 4, 5} mod 7. 2
0, 2, 4, 5, 7, 9, 11, 12, 14, 16, 18, 19, 21, 23, 25, 26, 28, 30, 32, 33, 35, 37, 39, 40, 42, 44, 46, 47, 49, 51, 53, 54, 56, 58, 60, 61, 63, 65, 67, 68, 70, 72, 74, 75, 77, 79, 81, 82, 84, 86, 88, 89, 91, 93, 95, 96 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..56.

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

FORMULA

a(n) = floor(floor((7n + 2)/2)/2).

a(n) = floor((7n-5)/4). - Gary Detlefs, Mar 07 2010

G.f.: x^2*(2+2*x+x^2+2*x^3) / ( (1+x)*(x^2+1)*(x-1)^2 ). - R. J. Mathar, Dec 04 2011

From Wesley Ivan Hurt, Dec 03 2014: (Start)

a(n) = a(n-1) + a(n-4) - a(n-5), n>5;

a(n) = (14*n-13-(-1)^n+2*i^n*(-1)^((3+(-1)^n)/4))/8, where i = sqrt(-1);

a(n) = A047215(n-1) - A057353(n-1). (End)

MAPLE

A047379:=n->floor((7*n-5)/4): seq(A047379(n), n=1..100); # Wesley Ivan Hurt, Dec 03 2014

MATHEMATICA

Select[Range[0, 100], MemberQ[{0, 2, 4, 5}, Mod[#, 7]]&] (* Harvey P. Dale, Apr 10 2014 *)

PROG

(MAGMA) [Floor((7*n-5)/4) : n in [1..100]]; // Wesley Ivan Hurt, Dec 03 2014

CROSSREFS

Cf. A047215, A057353.

Sequence in context: A169581 A184858 A083026 * A093848 A049039 A325101

Adjacent sequences:  A047376 A047377 A047378 * A047380 A047381 A047382

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified September 20 20:02 EDT 2020. Contains 337265 sequences. (Running on oeis4.)