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A061197 Table by antidiagonals T(n,k) of number of partitions of k where the largest part is less than or equal to n and where there are no more than two of any particular sized part. 1
1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 0, 2, 1, 1, 0, 0, 1, 2, 1, 1, 0, 0, 2, 2, 2, 1, 1, 0, 0, 1, 3, 2, 2, 1, 1, 0, 0, 1, 3, 4, 2, 2, 1, 1, 0, 0, 0, 3, 4, 4, 2, 2, 1, 1, 0, 0, 0, 3, 5, 5, 4, 2, 2, 1, 1, 0, 0, 0, 3, 5, 6, 5, 4, 2, 2, 1, 1, 0, 0, 0, 2, 7, 7, 7, 5, 4, 2, 2, 1, 1, 0, 0, 0, 2, 6, 9, 8, 7, 5, 4, 2, 2, 1, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,13

LINKS

Table of n, a(n) for n=0..104.

FORMULA

T(n, k)=T(n-1, k)+T(n-1, n-k)+T(n-1, n-2k) [with T(0, 0)=1 and T(n, k)=0 if n or k are negative].

EXAMPLE

Rows start (1,0,0,0,0,0,...), (1,1,1,0,0,0,...), (1,1,2,1,2,1,...), (1,1,2,2,3,3,...) etc. T(3,5)=3 since 5 can be written as 3+2 or 3+1+1 or 2+2+1.

CROSSREFS

Main diagonal is A000726.

Sequence in context: A249609 A232442 A107110 * A196346 A261884 A035178

Adjacent sequences:  A061194 A061195 A061196 * A061198 A061199 A061200

KEYWORD

nonn,tabl

AUTHOR

Henry Bottomley, Apr 20 2001

STATUS

approved

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Last modified December 6 00:38 EST 2016. Contains 278771 sequences.