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 A160357 Sign of first differences of Recamán's sequence A005132. 10
 1, 1, 1, 1, -1, 1, 1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, 1, 1, -1, 1, -1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, 1, 1, -1, 1, -1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, 1, 1, -1, 1, -1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS T. D. Noe, Table of n, a(n) for n = 0..10000 FORMULA a(n) = sign(A005132(n)-A005132(n-1)) = sign(A160356(n)) = (-1)^A160351(n) = -(-1)^A076213(n-1). a(n) = (A005132(n)-A005132(n-1))/n. - N. J. A. Sloane, Jul 15 2011 A160357 = chi_A057165 - chi_A057166, where chi_A denotes the characteristic function of (the set of values of) A. MAPLE A160357 := proc(n) sign( A005132(n)-A005132(n-1)) ; end proc: # R. J. Mathar, Apr 01 2012 MATHEMATICA f[s_List] := Module[{a = s[[-1]], n = Length[s]}, Append[s, If[a > n && FreeQ[s, a - n], a - n, a + n]]]; Nest[f, {0}, 100] // Differences // Sign (* Jean-François Alcover, Apr 19 2020, using Robert G. Wilson v's code for A005132 *) CROSSREFS Cf. A005132, A119632. Sequence in context: A212157 A131554 A153881 * A186039 A332433 A057077 Adjacent sequences: A160354 A160355 A160356 * A160358 A160359 A160360 KEYWORD sign AUTHOR M. F. Hasler, Jun 03 2009 EXTENSIONS a(0)=1 added by N. J. A. Sloane, May 01 2020 STATUS approved

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Last modified December 4 23:05 EST 2022. Contains 358572 sequences. (Running on oeis4.)