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A227289 Smallest m such that gcd(A227113(m+1), A227113(m)) = n. 2
1, 2, 4, 10, 6, 177, 8, 514, 500, 349, 14, 4791, 16, 5949, 1623, 863, 20, 2629, 22, 5113, 2043, 3211, 28, 7347, 4593, 11911, 1647, 12819, 34, 27325, 36, 15755, 34527, 29319, 5459, 2797, 42, 24535, 20145, 15511, 46, 26523, 48, 64895, 13335, 40769, 54, 43835, 184041 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
A227288(a(n)) = n and A227288(m) <> n for m < a(n).
LINKS
EXAMPLE
. n | a(n) | A227288(a(n)) = gcd(A227113(a(n)),A227113(a(n)+1))
. ---+--------+--------------- -----------------------------------
. 1 | 1 | 1 = gcd(1,2)
. 2 | 2 | 2 = gcd(2,4)
. 3 | 4 | 3 = gcd(3,6)
. 4 | 10 | 4 = gcd(8,12)
. 5 | 6 | 5 = gcd(5,10)
. 6 | 177 | 6 = gcd(168,162)
. 7 | 8 | 7 = gcd(7,14)
. 8 | 514 | 8 = gcd(472,480)
. 9 | 500 | 9 = gcd(459,468)
. 10 | 349 | 10 = gcd(330,320)
. 11 | 14 | 11 = gcd(11,22)
. 12 | 4791 | 12 = gcd(4524,4512)
PROG
(Haskell)
import Data.List (elemIndex); import Data.Maybe (fromJust)
a227289 = (+ 1) . fromJust . (`elemIndex` a227288_list)
CROSSREFS
Sequence in context: A130334 A320537 A331708 * A200742 A178729 A124108
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jul 05 2013
STATUS
approved

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Last modified March 28 07:20 EDT 2024. Contains 371235 sequences. (Running on oeis4.)