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A276989 Reversion of x - x^2 - x^6. 2
1, 1, 2, 5, 14, 43, 140, 474, 1650, 5863, 21170, 77441, 286372, 1068790, 4020704, 15230470, 58044354, 222401745, 856235030, 3310615055, 12849946406, 50051007940, 195571906140, 766413504375, 3011469930300, 11862075827007, 46830440626612, 185271557066226 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
FORMULA
a(n) = (Sum_{j=0..(n-1)/2} C(n-1-4*j,j)*C(2*n-4*j-2,n-1))/n.
MATHEMATICA
Table[Sum[Binomial[n-1-4*j, j]Binomial[2*n-4*j-2, n-1], {j, 0, (n-1)/2}]/n, {n, 1, 25}]
CROSSREFS
Sequence in context: A149880 A066351 A181496 * A272461 A213264 A029889
KEYWORD
nonn
AUTHOR
STATUS
approved

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Last modified July 19 19:50 EDT 2024. Contains 374436 sequences. (Running on oeis4.)