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A114861 a(n) is smallest positive integer not among the earlier terms of the sequence, not equal to n and which is coprime to its adjacent terms in the sequence. 3
2, 1, 4, 3, 7, 5, 6, 11, 8, 9, 10, 13, 12, 17, 14, 15, 16, 19, 18, 23, 20, 21, 22, 25, 24, 29, 26, 27, 28, 31, 30, 37, 32, 33, 34, 35, 36, 41, 38, 39, 40, 43, 42, 47, 44, 45, 46, 49, 48, 53, 50, 51, 52, 55, 54, 59, 56, 57, 58, 61, 60, 67, 62, 63, 64, 65, 66, 71, 68, 69, 70, 73 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Sequence is a permutation of the positive integers. (Inverse permutation is sequence A114862.)

LINKS

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

EXAMPLE

a(8) = 11 since 11 is the smallest positive integer not among the first 7 terms of the sequence, not equal to 8 and which is coprime to a(7) = 6.

MATHEMATICA

f[l_] := Block[{k = 1}, While[k == Length[l] + 1 || MemberQ[l, k] || GCD[k, Last[l]] > 1, k++ ]; Return[Append[l, k]]; ]; Nest[f, {}, 76] (* Ray Chandler, Jan 02 2006 *)

CROSSREFS

Cf. A114862.

Sequence in context: A281853 A077912 A077963 * A086512 A120751 A054082

Adjacent sequences:  A114858 A114859 A114860 * A114862 A114863 A114864

KEYWORD

nonn

AUTHOR

Leroy Quet, Jan 02 2006

EXTENSIONS

More terms from Ray Chandler and Klaus Brockhaus, Jan 02 2006

STATUS

approved

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Last modified June 16 13:05 EDT 2021. Contains 345057 sequences. (Running on oeis4.)