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URL: https://oeis.org/A154629

⇱ A154629 - OEIS

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A154629
Period 9: repeat [9, 3, 1, 3, 3, 1, 3, 9, 1].
2
9, 3, 1, 3, 3, 1, 3, 9, 1, 9, 3, 1, 3, 3, 1, 3, 9, 1, 9, 3, 1, 3, 3, 1, 3, 9, 1, 9, 3, 1, 3, 3, 1, 3, 9, 1, 9, 3, 1, 3, 3, 1, 3, 9, 1, 9, 3, 1, 3, 3, 1, 3, 9, 1, 9, 3, 1, 3, 3, 1, 3, 9, 1, 9, 3, 1, 3, 3, 1, 3, 9, 1, 9, 3, 1, 3, 3, 1, 3, 9, 1, 9, 3, 1, 3, 3
OFFSET
0,1
COMMENTS
Greatest common divisor of (n+1)^2-1 and (n+1)^2+8. - Bruno Berselli, Mar 08 2017
FORMULA
a(n) = A147674(n)/9.
a(n) = A005563(n) / A144454(n+1) for n>0.
From Colin Barker, Dec 21 2017: (Start)
G.f.: (9 + 3*x + x^2 + 3*x^3 + 3*x^4 + x^5 + 3*x^6 + 9*x^7 + x^8) / ((1 - x)*(1 + x + x^2)*(1 + x^3 + x^6)).
a(n) = a(n-9) for n>8.
(End)
MATHEMATICA
With[{n=5}, PadLeft[{}, 9n, {9, 3, 1, 3, 3, 1, 3, 9, 1}]] (* Harvey P. Dale, Oct 22 2011 *)
PROG
(PARI) Vec((9 + 3*x + x^2 + 3*x^3 + 3*x^4 + x^5 + 3*x^6 + 9*x^7 + x^8) / ((1 - x)*(1 + x + x^2)*(1 + x^3 + x^6)) + O(x^100)) \\ Colin Barker, Dec 21 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Jan 13 2009
STATUS
approved