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A140975 Period length 20: repeat 1, 3, 8, 8, 9, 1, 6, 6, 7, 9, 4, 4, 5, 7, 2, 2, 3, 5, 0, 0. 1
1, 3, 8, 8, 9, 1, 6, 6, 7, 9, 4, 4, 5, 7, 2, 2, 3, 5, 0, 0, 1, 3, 8, 8, 9, 1, 6, 6, 7, 9, 4, 4, 5, 7, 2, 2, 3, 5, 0, 0, 1, 3, 8, 8, 9, 1, 6, 6, 7, 9, 4, 4, 5, 7, 2, 2, 3, 5, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The period contains each digit from 0 to 9 twice.

LINKS

Table of n, a(n) for n=0..59.

FORMULA

a(n) = A011377(n) mod 10.

a(n)=(1/380)*{-10*(n mod 20)+9*[(n+1) mod 20]+104*[(n+2) mod 20]-29*[(n+3) mod 20]-10*[(n+4) mod 20]+9*[(n+5) mod 20]+104*[(n+6) mod 20]-29*[(n+7) mod 20]-10*[(n+8) mod 20]+9*[(n+9) mod 20]+104*[(n+10) mod 20]-29*[(n+11) mod 20]-10*[(n+12) mod 20]+9*[(n+13) mod 20]-86*[(n+14) mod 20]+161*[(n+15) mod 20]-10*[(n+16) mod 20]+9*[(n+17) mod 20]-86*[(n+18) mod 20]-29*[(n+19) mod 20]}, with n>=0 [From Paolo P. Lava, Oct 23 2008]

a(n) = +a(n-1) -a(n-2) +a(n-3) -a(n-4) +a(n-5) -a(n-6) +a(n-7) -a(n-8) +a(n-9) -a(n-10) +a(n-11) -a(n-12) +a(n-13) -a(n-14) +a(n-15) -a(n-16) +a(n-17) -a(n-18) +a(n-19).

G.f. ( -1 -2*x -6*x^2 -7*x^4 -12*x^6 -13*x^8 +4*x^9 -8*x^10 -9*x^12 +2*x^13 -5*x^16 -2*x^3 +4*x^11 +2*x^15 +6*x^5 +6*x^7 -4*x^14 ) / ( (x-1) *(1+x^2) *(1+x+x^2+x^3+x^4) *(1-x+x^2-x^3+x^4) *(1-x^2+x^4-x^6+x^8) ). - R. J. Mathar, Jul 08 2011

CROSSREFS

Sequence in context: A288094 A131596 A332892 * A065481 A032538 A168209

Adjacent sequences:  A140972 A140973 A140974 * A140976 A140977 A140978

KEYWORD

nonn,easy

AUTHOR

Paul Curtz, Jul 28 2008

STATUS

approved

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Last modified December 4 15:27 EST 2020. Contains 338927 sequences. (Running on oeis4.)