A093412 - OEIS

A093412

Triangle read by rows: a(n, k) is the numerator of (n + (n-1) + ... + (n-k+1))/(1 + 2 + ... + k), 0 < k <= n.

1, 2, 1, 3, 5, 1, 4, 7, 3, 1, 5, 3, 2, 7, 1, 6, 11, 5, 9, 4, 1, 7, 13, 3, 11, 5, 9, 1, 8, 5, 7, 13, 2, 11, 5, 1, 9, 17, 4, 3, 7, 13, 3, 11, 1, 10, 19, 9, 17, 8, 15, 7, 13, 6, 1, 11, 7, 5, 19, 3, 17, 2, 5, 7, 13, 1, 12, 23, 11, 21, 10, 19, 9, 17, 8, 15, 7, 1, 13, 25, 6, 23, 11, 3, 5, 19, 9, 17, 4

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OFFSET

1,2

COMMENTS

A093415 gives the corresponding denominators.

LINKS

Table of n, a(n) for n=1..89.

FORMULA

a(n, k) = (2n+1-k)/gcd(2n+1-k, k+1).

EXAMPLE

Triangle a(n,k) (with rows n >= 1 and columns k >= 1) begins as follows:

2, 1;