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A134301 Periodic sequence (0, 2, 6, 2, 0). 0
0, 2, 6, 2, 0, 0, 2, 6, 2, 0, 0, 2, 6, 2, 0, 0, 2, 6, 2, 0, 0, 2, 6, 2, 0, 0, 2, 6, 2, 0, 0, 2, 6, 2, 0, 0, 2, 6, 2, 0, 0, 2, 6, 2, 0, 0, 2, 6, 2, 0, 0, 2, 6, 2, 0, 0, 2, 6, 2, 0, 0, 2, 6, 2, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Also: twice the partial sums of A117444. - R. J. Mathar, Feb 01 2008

REFERENCES

Rozsa Peter, Leon Harkleroad, Mathematics is Beautiful, Math. Intellig., 12 (No. 1, 1990), 58-64.

LINKS

Table of n, a(n) for n=0..64.

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

FORMULA

a(n) = n(n+1) mod 10

O.g.f.: -2/(x-1)+(2*x^3+2*x^2-2*x-2)/(1+x+x^2+x^3+x^4). a(n)=a(n-5). - R. J. Mathar, Feb 01 2008

a(n)=(1/5)*{(n mod 5)+3*[(n+1) mod 5]+5*[(n+2) mod 5]-3*[(n+3) mod 5]-[(n+4) mod 5]}, with n>=0 - Paolo P. Lava, Feb 05 2008

MATHEMATICA

PadRight[{}, 70, {0, 2, 6, 2, 0}] (* Harvey P. Dale, Mar 22 2012 *)

PROG

(PARI) a(n)=[0, 2, 6, 2, 0][n%5+1] \\ Charles R Greathouse IV, Jul 13 2016

CROSSREFS

Sequence in context: A117214 A185972 A182918 * A168294 A004544 A010590

Adjacent sequences:  A134298 A134299 A134300 * A134302 A134303 A134304

KEYWORD

nonn,easy

AUTHOR

Franz Vrabec, Jan 30 2008

STATUS

approved

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Last modified April 14 18:25 EDT 2021. Contains 342951 sequences. (Running on oeis4.)