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 A113925 a(1)=0. a(1)=1. a(n+2) = gcd(a(n+1) + a(n), n). 2
 0, 1, 1, 2, 3, 1, 1, 2, 1, 1, 1, 2, 1, 3, 1, 2, 3, 1, 1, 2, 1, 1, 1, 2, 1, 3, 1, 2, 3, 1, 1, 2, 1, 1, 1, 2, 1, 3, 1, 2, 3, 5, 1, 6, 1, 1, 1, 2, 1, 3, 1, 2, 3, 1, 1, 2, 1, 1, 1, 2, 1, 3, 1, 2, 3, 1, 1, 2, 1, 1, 1, 2, 1, 3, 1, 2, 3, 1, 1, 2, 1, 1, 1, 2, 1, 3, 1, 2, 3, 1, 1, 2, 1, 1, 1, 2, 1, 3, 1, 2, 3, 5, 1, 6, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS a(1)'s value is arbitrary. Replacing a(1) with any integer would not alter the rest of the sequence. LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 EXAMPLE a(14) = gcd(a(13) + a(12), 12) = gcd(1+2, 12) = gcd(3, 12) = 3. MAPLE a[1]:=0: a[2]:=1: for n from 3 to 135 do a[n]:=gcd(a[n-1]+a[n-2], n-2) od: seq(a[n], n=1..117); # Emeric Deutsch, Feb 07 2006 MATHEMATICA nxt[{n_, a_, b_}]:={n+1, b, GCD[a+b, n-1]}; NestList[nxt, {2, 0, 1}, 110][[All, 2]] (* Harvey P. Dale, Jun 13 2017 *) CROSSREFS Sequence in context: A135508 A030413 A139434 * A328231 A180466 A105083 Adjacent sequences:  A113922 A113923 A113924 * A113926 A113927 A113928 KEYWORD nonn AUTHOR Leroy Quet, Jan 30 2006 EXTENSIONS More terms from Emeric Deutsch, Feb 07 2006 STATUS approved

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Last modified August 7 19:57 EDT 2020. Contains 336279 sequences. (Running on oeis4.)