A027113 Triangular array T given by rows: T(n,0)=1 for n >= 0, T(n,1)=1,T(n,2)=2 for n >= 1 and for n >= 2, T(n,k)=T(n-1,k-3)+T(n-1,k-2)+T(n-1,k-1) for 3<=k<=2n-1, T(n,2n)=T(n-1,2n-3)+T(n-1,2n-2).

1, 1, 1, 2, 1, 1, 2, 4, 3, 1, 1, 2, 4, 7, 9, 7, 1, 1, 2, 4, 7, 13, 20, 23, 16, 1, 1, 2, 4, 7, 13, 24, 40, 56, 59, 39, 1, 1, 2, 4, 7, 13, 24, 44, 77, 120, 155, 154, 98, 1, 1, 2, 4, 7, 13, 24, 44, 81, 145, 241, 352, 429, 407, 252, 1, 1, 2, 4, 7, 13, 24

Offset

1,4

Comments

The rows are of lengths 1, 3, 5, 7, ...

Links

Table of n, a(n) for n=1..71.

Example

1; 1,1,2; 1,1,2,4,3; 1,1,2,4,7,9,7; 1,1,2,4,7,13,20,23,16; ...

Crossrefs

Sequence in context: A356718 A260931 A293819 * A096470 A085143 A321029

Adjacent sequences: A027110 A027111 A027112 * A027114 A027115 A027116

Keyword

nonn,tabf

Author

Clark Kimberling

Status

approved