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A106362
Number of rooted planar trees in which no branch is identical to its adjacent neighbor.
2
1, 1, 1, 2, 4, 10, 28, 77, 221, 650, 1951, 5920, 18211, 56509, 176919, 557786, 1769966, 5647568, 18110734, 58335561, 188658338, 612337013, 1994058293, 6513153445, 21332562178, 70048092196, 230550762108, 760462920317
OFFSET
1,4
FORMULA
G.f.: x+x*B(x) where B(x) is g.f. of CycleBG transform of A106361.
CycleBG transform T(A) = invMOEBIUS(invEULER(Carlitz(A)) + A(x^2) - A) + A.
Carlitz transform T(A(x)) has g.f. 1/(1-sum(k>0, (-1)^(k+1)*A(x^k))).
CROSSREFS
Sequence in context: A128933 A173781 A340825 * A271896 A148109 A099216
KEYWORD
nonn
AUTHOR
Christian G. Bower, Apr 29 2005
STATUS
approved