A280753 Denominators of triangle related to enumeration of minimal 2-covers of a labeled n-set.

1, 3, 3, 7, 2, 7, 15, 5, 21, 15, 31, 3, 651, 186, 31, 63, 7, 651, 651, 651, 63, 127, 4, 11811, 15748, 11811, 762, 127, 255, 9, 66929, 602361, 602361, 10795, 32385, 255

Offset

1,2

Links

Table of n, a(n) for n=1..36.

Octavio A. Agustín-Aquino, Archimedes' quadrature of the parabola and minimal covers, arXiv:1602.05279 [math.CO], 2016.

Example

Triangle begins:
1,
1/3,   1/3,
1/7,   1/2,      1/7,
1/15,  3/5,     10/21,         1/15,
1/31,  2/3,    865/651,       71/186,       1/31,
1/63,  5/7,   2630/651,     1427/651,     181/651,     1/63,
1/127, 3/4, 163133/11811, 306553/15748, 36667/11811, 145/762, 1/127,
...

Crossrefs

Cf. A022166, A057963, A280752.

Sequence in context: A059527 A215235 A101457 * A076217 A256784 A324543

Adjacent sequences: A280750 A280751 A280752 * A280754 A280755 A280756

Keyword

nonn,tabl,more

Author

N. J. A. Sloane, Jan 15 2017

Status

approved