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A137155
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a(n) = Sum_{k=0..[n/2]} C(2^k + n-2k-1, n-2k); equals the antidiagonal sums of triangle A137153.
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2
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1, 1, 2, 3, 5, 9, 17, 35, 80, 201, 561, 1771, 6298, 25217, 115440, 605243, 3609754, 24742305, 196470603, 1792166979, 18817616610, 230233601737, 3268914688382, 53509699527491, 1020486454701731, 22777217813040393, 589097686208575727
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OFFSET
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0,3
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LINKS
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PROG
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(PARI) a(n)=sum(k=0, n\2, binomial(2^k+n-2*k-1, n-2*k))
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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