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A064426 First differences of A064413. 2
1, 2, 2, -3, 6, 3, -4, 2, -5, 10, 3, -4, -7, 14, 3, -8, 4, 2, -11, 22, -6, 3, -5, 10, -7, -2, -13, 26, -3, -4, 2, -17, 34, -9, -4, -19, 38, -12, -5, 4, 2, -23, 46, -21, 2, 2, 2, 2, -7, 14, -3, -5, 10, 5, -12, -29, 58, -21, -4, -31, 62, -21, -8, 4, 6, -37, 74, -36, 3, -2, 4, 2, -41, 82, -42, 3, -7, 11, -2, -43 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
J. C. Lagarias, E. M. Rains and N. J. A. Sloane, The EKG sequence, Exper. Math. 11 (2002), 437-446.
MATHEMATICA
ekg[s_] := Block[{m = s[[-1]], k = 3}, While[MemberQ[s, k] || GCD[m, k] == 1, k++]; Append[s, k]]; Nest[ekg, {1, 2}, 100] // Differences (* Jean-François Alcover, Sep 10 2018, after Robert G. Wilson v *)
PROG
(Haskell)
a064426 n = a064426_list !! (n-1)
a064426_list = zipWith (-) (tail a064413_list) a064413_list
-- Reinhard Zumkeller, Sep 17 2001
CROSSREFS
Sequence in context: A362199 A260389 A291372 * A051173 A322744 A128228
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Oct 02 2001
STATUS
approved

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Last modified March 29 02:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)