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A111952 a(n) = 3*n mod 7. 1
0, 3, 6, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1, 4, 0, 3, 6, 2, 5, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Period 7: repeat [0, 3, 6, 2, 5, 1, 4].

Draw a regular heptagon with vertices labeled 0..6 going clockwise. Choose any seven consecutive values of a(n) and connect the corresponding vertices in that order with straight lines. This results in a clockwise-inscribed seven-pointed star that remains unbroken during construction. - Wesley Ivan Hurt, Apr 10 2015

LINKS

Table of n, a(n) for n=0..89.

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

FORMULA

G.f.: (3*x+6*x^2+2*x^3+5*x^4+x^5+4*x^6)/(1-x^7).

a(n) = mod(n*(7*n-1)/2, 7) = mod(A022264(n), 7).

Recurrence: a(n) = a(n-7) for n > 6. - Wesley Ivan Hurt, Apr 10 2015

a(n) = (21 + 4*(n mod 7) - 3*((n+1) mod 7) + 4*((n+2) mod 7) - 3*((n+3) mod 7) + 4*((n+4) mod 7) - 3*((n+5) mod 7) - 3*((n+6) mod 7))/7. - Wesley Ivan Hurt, Dec 23 2016

a(n) = A010876(3*n). - R. J. Mathar, Jan 15 2021

MAPLE

A111952:=n->3*n mod 7: seq(A111952(n), n=0..100); # Wesley Ivan Hurt, Apr 10 2015

MATHEMATICA

Mod[3 Range[0, 100], 7] (* Wesley Ivan Hurt, Apr 10 2015 *)

PROG

(PARI) a(n)=3*n%7 \\ Charles R Greathouse IV, Jul 23, 2011

(MAGMA) [3*n mod 7 : n in [0..100]]; // Wesley Ivan Hurt, Apr 10 2015

CROSSREFS

Cf. A022264.

Sequence in context: A333010 A319513 A160590 * A068466 A194076 A194040

Adjacent sequences:  A111949 A111950 A111951 * A111953 A111954 A111955

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Aug 22 2005

STATUS

approved

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Last modified April 15 01:24 EDT 2021. Contains 342974 sequences. (Running on oeis4.)