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A298567 a(n) = Sum_{k=0..2*n/3} C(n-k,2*k-n)^2. 0
1, 0, 1, 1, 1, 4, 2, 9, 10, 17, 37, 41, 102, 136, 251, 450, 667, 1325, 2011, 3658, 6246, 10293, 18686, 30461, 54183, 92169, 157438, 276414, 466579, 818256, 1400509, 2419379, 4202829, 7208342, 12556360, 21621891, 37480728, 64965461, 112227269 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

LINKS

Table of n, a(n) for n=0..38.

FORMULA

G.f.: 1/sqrt((1-x^2)^2+x^6-2*x^5-2*x^3).

PROG

(Maxima)

a(n):=sum(binomial(n-k, 2*k-n)^2, k, 0, 2*n/3);

CROSSREFS

Cf. A182878.

Sequence in context: A242049 A179398 A233295 * A006172 A171631 A052915

Adjacent sequences:  A298564 A298565 A298566 * A298568 A298569 A298570

KEYWORD

nonn

AUTHOR

Vladimir Kruchinin, Jan 21 2018

STATUS

approved

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Last modified November 22 18:55 EST 2019. Contains 329410 sequences. (Running on oeis4.)