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 A162922 Square array read by antidiagonals: m is the a(n,m)th positive integer among those which are coprime to n. Or a(n,m) = 0 if m and n are not coprime. 1
 1, 1, 2, 1, 0, 3, 1, 2, 2, 4, 1, 0, 0, 0, 5, 1, 2, 2, 3, 3, 6, 1, 0, 3, 0, 4, 0, 7, 1, 2, 0, 4, 3, 0, 4, 8, 1, 0, 3, 0, 0, 0, 5, 0, 9, 1, 2, 2, 4, 2, 5, 4, 6, 5, 10, 1, 0, 0, 0, 5, 0, 6, 0, 0, 0, 11, 1, 2, 2, 3, 3, 6, 3, 7, 5, 7, 6, 12, 1, 0, 3, 0, 4, 0 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 EXAMPLE Rows 1 through 7 of the array: n=1: 1,2,3,4,5,6,7,8,9,... n=2: 1,0,2,0,3,0,4,0,5,... n=3: 1,2,0,3,4,0,5,6,0,... n=4: 1,0,2,0,3,0,4,0,5,... n=5: 1,2,3,4,0,5,6,7,8,... n=6: 1,0,0,0,2,0,3,0,0,... n=7: 1,2,3,4,5,6,0,7,8,... MAPLE N:= 20: # for the first N antidiagonals for n from 1 to N do   t:= 0:   for m from 1 to N+1-n do     if igcd(m, n)=1 then       t:= t+1; T[n, m]:= t;     else T[n, m]:= 0     fi   od od: [seq(seq(T[i-m, m], m=1..i-1), i=1..N+1)]; # Robert Israel, Sep 05 2016 CROSSREFS Sequence in context: A141543 A182720 A146540 * A246180 A102057 A276276 Adjacent sequences:  A162919 A162920 A162921 * A162923 A162924 A162925 KEYWORD nonn,tabl AUTHOR Leroy Quet, Jul 17 2009 EXTENSIONS More terms from Robert Israel, Sep 05 2016 STATUS approved

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Last modified December 12 01:57 EST 2019. Contains 329948 sequences. (Running on oeis4.)