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A227288 Greatest common divisor of consecutive terms in A227113. 3
1, 2, 1, 3, 1, 5, 1, 7, 2, 4, 3, 3, 1, 11, 1, 13, 2, 2, 1, 17, 1, 19, 2, 4, 3, 3, 1, 23, 1, 5, 2, 4, 1, 29, 1, 31, 1, 3, 1, 5, 1, 37, 1, 3, 1, 41, 1, 43, 2, 4, 3, 5, 1, 47, 1, 7, 1, 3, 2, 4, 1, 53, 1, 5, 1, 3, 1, 59, 1, 61, 2, 2, 1, 67, 2, 2, 1, 3, 1, 71, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(n) = GCD(A227113(n),A227113(n+1));
a(2*n) > 1 by definition of A227113;
9 is the smallest odd number m with a(m) > 1: a(9) = GCD(A227113(9),A227113(10)) = GCD(14,8) = 2;
a(A227289(n)) = n and a(m) <> n for m < A227289(n).
LINKS
PROG
(Haskell)
a227288 n = a227288_list !! (n-1)
a227288_list = zipWith gcd (tail a227113_list) a227113_list
CROSSREFS
Sequence in context: A130008 A101809 A127203 * A336752 A126132 A129982
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jul 05 2013
STATUS
approved

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Last modified March 28 14:38 EDT 2024. Contains 371254 sequences. (Running on oeis4.)