A064426 First differences of A064413.

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

Offset

1,2

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

J. C. Lagarias, E. M. Rains and N. J. A. Sloane, The EKG sequence, Exper. Math. 11 (2002), 437-446.

Index entries for sequences related to EKG sequence

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

Adjacent sequences: A064423 A064424 A064425 * A064427 A064428 A064429

Keyword

sign

Author

N. J. A. Sloane, Oct 02 2001

Status

approved