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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
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, 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, 11, 7, 1, 1, 7, 11, 13, 14, 10, 6, 2, 2, 6, 10, 14, 15, 13, 11
OFFSET
0,4
LINKS
PROG
(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
CROSSREFS
Sum of numerator and denominator is given by A038567.
Sequence in context: A355792 A286093 A078827 * A328732 A130795 A367634
KEYWORD
nonn,look
AUTHOR
Ron R. King, Mar 07 2009
EXTENSIONS
Terms a(56) and beyond from Andrew Howroyd, Feb 03 2021
STATUS
approved