A059882 As upper right triangle: ascending wiggly sums to n where first term is k (sums in which terms alternately increase and decrease; zigzag partitions).

1, 0, 1, 1, 0, 1, 2, 0, 0, 1, 2, 1, 0, 0, 1, 4, 2, 0, 0, 0, 1, 6, 3, 1, 0, 0, 0, 1, 9, 4, 2, 0, 0, 0, 0, 1, 14, 7, 3, 1, 0, 0, 0, 0, 1, 23, 10, 5, 2, 0, 0, 0, 0, 0, 1, 35, 17, 7, 3, 1, 0, 0, 0, 0, 0, 1, 55, 26, 11, 5, 2, 0, 0, 0, 0, 0, 0, 1, 87, 41, 17, 8, 3, 1, 0, 0, 0, 0, 0, 0, 1, 136, 64, 28, 11, 5, 2

Offset

1,7

Links

Table of n, a(n) for n=1..97.

Formula

If n>k>0 T(n, k)=sum_j[S(n-k, j)] over j>k and if n>0 T(n, n)=1; where S(n, k)=A059883(n, k) and if n>k>0, S(n, k)=sum_j[T(n-k, j)] over k>j (note reversal) and if n>0 S(n, n)=1.

Example

Rows start (1,0,1,2,2,...), (1,0,0,1,...), (1,0,0,...) etc. T(10,4)=2 since 10 can be written as 4+6 or 4+5+1.

Crossrefs

Column sums are A025048. Cf. A025047, A025049, A059881, A059883.

Sequence in context: A324044 A364046 A001899 * A303206 A094247 A053694

Adjacent sequences: A059879 A059880 A059881 * A059883 A059884 A059885

Keyword

nonn,tabl

Author

Henry Bottomley, Feb 05 2001

Status

approved