A127715 Rightmost border of triangle A127714: a(n) = A127714(n, (n+1)*(n+2)/2 - 1).

1, 1, 3, 14, 86, 645, 5662, 56632, 633545, 7820115, 105401961, 1538517351, 24157841308, 405778641302, 7256711524298, 137607733327779, 2757147167433326, 58188668578629283, 1289965088962987961

Offset

0,3

Links

Paul D. Hanna, Table of n, a(n), n = 0..100.

Formula

From Gary W. Adamson, Aug 02 2011: (Start)

a(n) = upper left term of M^n, M is an infinite square production matrix in which nonzero terms = A033184 with the first "1" deleted, as follows: M =

1, 1, 0, 0, 0, 0, ...

2, 2, 1, 0, 0, 0, ...

5, 5, 3, 1, 0, 0, ...

14, 14, 9, 4, 1, 0, ...

42, 42, 28, 14, 5, 1, ...

... (End)

Example

a(3) = 14 = the upper left term of M^3.

Crossrefs

Cf. A127714, A127716, A033184

Sequence in context: A308940 A276313 A074520 * A307440 A087912 A308878

Adjacent sequences: A127712 A127713 A127714 * A127716 A127717 A127718

Keyword

nonn

Author

Paul D. Hanna, Jan 24 2007

Status

approved