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A108457
Number of partitions of (n,n) into pairs (i,j) with i>0, j>=0.
4
1, 1, 3, 8, 23, 60, 161, 404, 1011, 2440, 5804, 13462, 30798, 69082, 152862, 333094, 716781, 1522534, 3198011, 6642274, 13657417, 27805917, 56097811, 112183092, 222496203, 437787036, 854936195, 1657526884, 3191478236, 6104379829, 11602006003, 21916355387
OFFSET
0,3
COMMENTS
(a,b)+(x,y)=(a+x,b+y); unit is (0,0).
LINKS
FORMULA
a(n) = A091438(2n,n). - Alois P. Heinz, Sep 24 2018
EXAMPLE
(2,2)=(1,2)+(1,0)=(1,1)+(1,1), so a(2)=3.
CROSSREFS
Main diagonal of A108456.
Sequence in context: A027236 A353169 A027244 * A071618 A318861 A318819
KEYWORD
nonn
AUTHOR
Christian G. Bower, Jun 03 2005
STATUS
approved