A058805 Number of labeled vertically indecomposable lattices with a fixed top and bottom.

1, 1, 1, 0, 1, 7, 97, 1981, 56611, 2151857, 104905809, 6375234313, 472007532691, 41778412444165, 4351370158008721, 526176012328671173, 73022861716667028531, 11515387009980686269561

Offset

0,6

Links

Table of n, a(n) for n=0..17.

Crossrefs

a(n)=A058803(n)/(n*(n-1))=A058804(n)/(n-1).

Sequence in context: A083083 A022007 A174516 * A305137 A132061 A368439

Adjacent sequences: A058802 A058803 A058804 * A058806 A058807 A058808

Keyword

nonn,hard

Author

Christian G. Bower, Dec 28 2000

Status

approved