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A304580
Period 16: repeat 1,8,3,6,5,4,7,2,9,0,7,2,5,4,3,6.
2
1, 8, 3, 6, 5, 4, 7, 2, 9, 0, 7, 2, 5, 4, 3, 6, 1, 8, 3, 6, 5, 4, 7, 2, 9, 0, 7, 2, 5, 4, 3, 6, 1, 8, 3, 6, 5, 4, 7, 2, 9, 0, 7, 2, 5, 4, 3, 6, 1, 8, 3, 6, 5, 4, 7, 2, 9, 0, 7, 2, 5, 4, 3, 6, 1, 8, 3, 6, 5, 4, 7, 2, 9, 0, 7, 2, 5, 4, 3, 6, 1, 8, 3, 6, 5, 4
OFFSET
1,2
COMMENTS
Repeating sequences of alternating odd and even single digits that in pairs sum to 9, 11 or 7. Note that 1836547290725436 = 20202020197979796 / 11.
FORMULA
From Colin Barker, May 28 2018: (Start)
G.f.: x*(1 + 8*x + 2*x^2 - 2*x^3 + 2*x^4 - 2*x^5 + 2*x^6 - 2*x^7 + 3*x^8 + 6*x^9) / ((1 - x)*(1 + x)*(1 + x^8)).
a(n) = a(n-2) - a(n-8) + a(n-10) for n > 10.
(End)
MATHEMATICA
LinearRecurrence[{0, 1, 0, 0, 0, 0, 0, -1, 0, 1}, {1, 8, 3, 6, 5, 4, 7, 2, 9, 0}, 100] (* or *) PadRight[{}, 100, {1, 8, 3, 6, 5, 4, 7, 2, 9, 0, 7, 2, 5, 4, 3, 6}] (* Harvey P. Dale, Sep 28 2021 *)
PROG
(PARI) Vec(x*(1 + 8*x + 2*x^2 - 2*x^3 + 2*x^4 - 2*x^5 + 2*x^6 - 2*x^7 + 3*x^8 + 6*x^9) / ((1 - x)*(1 + x)*(1 + x^8)) + O(x^50)) \\ Colin Barker, May 28 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Halfdan Skjerning, May 15 2018
STATUS
approved