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A262430
Number of trees on n vertices with an even number of leaves.
2
1, 0, 1, 1, 1, 2, 3, 6, 12, 25, 54, 120, 278, 657, 1586, 3885, 9676, 24350, 61974, 159066, 411637, 1072477, 2812147, 7414611, 19650656, 52319946, 139898593, 375536661, 1011726481, 2734793731, 7415449225, 20165442393, 54986240994, 150314506170, 411889913114, 1131183374539, 3113153283443, 8584839296108, 23718157486109, 65645273392938, 181995130879151, 505374042479921, 1405493247220915, 3914493122094481, 10917513971606377, 30489195524251154, 85254349619909519, 238677545463592954, 668973050139380099, 1877097093098685409, 5272616851780131627
OFFSET
0,6
COMMENTS
For n>=0, a(n) + A262431(n) = A000055(n).
For n>=2, a(n) - A262431(n) = A262395(n).
FORMULA
G.f.: (A(x,1)+A(x,-1))/2, where A(x,y) is g.f. for A055290.
CROSSREFS
KEYWORD
nonn
AUTHOR
Max Alekseyev, Sep 22 2015
STATUS
approved