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A157806 Absolute value of the difference between numerator and denominator of fractions arranged by Cantor's ordering (1/1, 2/1, 1/2, 1/3, 3/1, 4/1, 3/2, 2/3, 1/4, 1/5, 5/1, 6/1, ...) with equivalent fractions removed. 1

%I #7 Feb 03 2021 21:41:46

%S 0,1,1,2,2,3,1,1,3,4,4,5,3,1,1,3,5,6,2,2,6,7,5,1,1,5,7,8,4,4,8,9,7,5,

%T 3,1,1,3,5,7,9,10,2,2,10,11,9,7,5,3,1,1,3,5,7,9,11,12,8,4,4,8,12,13,

%U 11,7,1,1,7,11,13,14,10,6,2,2,6,10,14,15,13,11

%N Absolute value of the difference between numerator and denominator of fractions arranged by Cantor's ordering (1/1, 2/1, 1/2, 1/3, 3/1, 4/1, 3/2, 2/3, 1/4, 1/5, 5/1, 6/1, ...) with equivalent fractions removed.

%H Andrew Howroyd, <a href="/A157806/b157806.txt">Table of n, a(n) for n = 0..10000</a>

%o (PARI) seq(n)={my(L=List(), r=1, k=1); while(#L<=n, if(k==r, r++; k=0); k++; if(gcd(k,r-k)==1, listput(L, abs(r-2*k)))); Vec(L)} \\ _Andrew Howroyd_, Feb 03 2021

%Y Sum of numerator and denominator is given by A038567.

%K nonn,look

%O 0,4

%A _Ron R. King_, Mar 07 2009

%E Terms a(56) and beyond from _Andrew Howroyd_, Feb 03 2021

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Last modified September 9 19:01 EDT 2024. Contains 375765 sequences. (Running on oeis4.)