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A145011 First differences of A007775. 4
6, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 2, 4, 6, 2, 6, 4, 2, 4, 2, 4, 6, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Also the first differences of A084968 divided by 7. - Antti Karttunen, May 01 2015
LINKS
FORMULA
Period 8: repeat 6,4,2,4,2,4,6,2.
a(n) = 2*((abs(abs((n mod 8) - 3) - 1) mod 3) + 1). - Pieter Stadhouders, Mar 09 2010
G.f.: x*(-2*x^7 - 6*x^6 - 4*x^5 - 2*x^4 - 4*x^3 - 2*x^2 - 4*x - 6)/(x^8 - 1). - Chai Wah Wu, Feb 16 2021
MATHEMATICA
Differences[Select[Range[400], GCD[#, 30]==1&]] (* Harvey P. Dale, Dec 07 2011 *)
PROG
(Haskell)
a145011 n = a145011_list !! (n-1)
a145011_list = zipWith (-) (tail a007775_list) a007775_list
-- Reinhard Zumkeller, Jan 06 2013
(PARI) a(n)=[4, 6, 4, 2, 4, 2][n%8+1] \\ Charles R Greathouse IV, Oct 20 2013
CROSSREFS
Multiplied by 7: row 4 of A257251.
Sequence in context: A114062 A338136 A028975 * A173625 A086036 A345644
KEYWORD
nonn,easy,changed
AUTHOR
Ki Punches, Feb 25 2009
EXTENSIONS
Edited by Omar E. Pol, Mar 02 2009
Offset corrected by Reinhard Zumkeller, Jan 06 2013
STATUS
approved

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Last modified March 19 04:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)