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A121711 Lexicographically earliest permutation of the natural numbers such that gcd(s(k-1)+1, a(k)) greater than gcd(s(k-1), a(k)+1), where s is the sum of preceding terms (A121712); a(1)=1. 5
1, 2, 4, 8, 6, 10, 12, 11, 15, 5, 3, 9, 18, 14, 7, 16, 22, 20, 23, 21, 19, 13, 24, 26, 25, 30, 35, 28, 32, 34, 36, 38, 40, 42, 39, 52, 33, 27, 45, 46, 48, 44, 41, 50, 43, 54, 56, 58, 60, 62, 55, 49, 51, 57, 63, 17, 64, 66, 61, 31, 68, 65, 69, 59, 37, 70, 72, 76, 53, 47, 74, 78 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

gcd(A121712(n-1)+1, a(n)) > gcd(A121712(n-1), a(n)+1);

inverse: A121713; fixed points: A121716;

a(a(n)) = A121714(n).

LINKS

Table of n, a(n) for n=1..72.

Index entries for sequences related to GCD's.

Index entries for sequences that are permutations of the natural numbers

CROSSREFS

Sequence in context: A320152 A022478 A320151 * A249681 A256561 A125597

Adjacent sequences:  A121708 A121709 A121710 * A121712 A121713 A121714

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Aug 18 2006

STATUS

approved

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Last modified January 20 23:16 EST 2020. Contains 331104 sequences. (Running on oeis4.)