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 A175306 Irregular array: row n contains A175307(n) terms. The first term of each row, a(n,1) = n. a(n,m) = the smallest integer > a(n,m-1) such that a(n,m), a(n,m)-1, and a(n,m)+1 are each coprime to all earlier terms in their row. The row terminates when a multiple of 2 or 3 is obtained. 2
 1, 2, 2, 3, 4, 5, 7, 12, 6, 7, 9, 8, 9, 10, 11, 13, 15, 12, 13, 15, 14, 15, 16, 17, 19, 21, 18, 19, 21, 20, 21, 22, 23, 25, 27, 24, 25, 27, 26, 27, 28, 29, 31, 33, 30, 31, 33, 32, 33, 34, 35, 37, 47, 52, 36, 37, 39, 38, 39, 40, 41, 43, 45, 42, 43, 45, 44, 45, 46, 47, 49, 51, 48, 49, 51, 50, 51, 52, 53 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Robert Israel, Table of n, a(n) for n = 1..10102 MAPLE A175306:= proc(n) local R, last, k, P; R:= n; last:= n; P:= n; while igcd(last, 6)=1 do   for k from last+1 do     if igcd(k-1, P) = 1 and igcd(k, P) = 1 and igcd(k+1, P) =1 then       R:= R, k; last:= k; P:= P*k; break     fi   od od; R end proc: map(A175306, [\$1..100]); # Robert Israel, Feb 10 2017 CROSSREFS Cf. A175307 Sequence in context: A186425 A034395 A032232 * A021993 A324743 A240011 Adjacent sequences:  A175303 A175304 A175305 * A175307 A175308 A175309 KEYWORD nonn,tabf AUTHOR Leroy Quet, Mar 26 2010 STATUS approved

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Last modified June 24 10:02 EDT 2019. Contains 324323 sequences. (Running on oeis4.)