A280752 Numerators of triangle related to enumeration of minimal 2-covers of a labeled n-set.

1, 1, 1, 1, 1, 1, 1, 3, 10, 1, 1, 2, 865, 71, 1, 1, 5, 2630, 1427, 181, 1, 1, 3, 163133, 306553, 36667, 145, 1, 1, 7, 3368938, 129115655, 46958822, 43662, 4036, 1

Offset: 1

Author

N. J. A. Sloane, Jan 15 2017

Keywords

• nonn
• tabl
• more

Examples

			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,
...
		

Links

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

Crossrefs

Cf. A022166, A057963, A280753.