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A129088 a(1)=a(2)=1. a(n) = GCD(a(n-1),n) + GCD(a(n-2),n). 1
1, 1, 2, 3, 2, 5, 2, 3, 4, 3, 2, 5, 2, 3, 4, 5, 2, 3, 2, 3, 4, 3, 2, 5, 6, 3, 6, 3, 2, 5, 2, 3, 4, 3, 2, 5, 2, 3, 4, 5, 2, 3, 2, 3, 4, 3, 2, 5, 2, 7, 2, 3, 2, 5, 6, 3, 6, 3, 2, 5, 2, 3, 4, 5, 6, 7, 2, 3, 4, 3, 2, 5, 2, 3, 4, 5, 2, 3, 2, 3, 4, 3, 2, 5, 6, 3, 6, 3, 2, 5, 2, 3, 4, 3, 2, 5, 2, 3, 4, 5, 2, 3, 2, 3, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

a(2n) is odd for all n >=1. a(2n-1) is even for all n >=2.

LINKS

Table of n, a(n) for n=1..105.

MAPLE

a[1]:=1: a[2]:=1: for n from 3 to 140 do a[n]:=gcd(a[n-1], n)+gcd(a[n-2], n) od: seq(a[n], n=1..140); - Emeric Deutsch, Apr 04 2007

CROSSREFS

Cf. A129089.

Sequence in context: A101876 A260218 A087986 * A086418 A100761 A027748

Adjacent sequences:  A129085 A129086 A129087 * A129089 A129090 A129091

KEYWORD

nonn

AUTHOR

Leroy Quet, Mar 29 2007

EXTENSIONS

More terms from Emeric Deutsch, Apr 04 2007

STATUS

approved

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Last modified December 13 11:33 EST 2018. Contains 318086 sequences. (Running on oeis4.)