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A182017
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Row square-sums of triangle A182013.
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1
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1, 5, 29, 165, 1020, 6606, 44805, 314299, 2266834, 16714004, 125501364, 956725836, 7387322749, 57669478609, 454492588153, 3611698593169, 28911762536992, 232949503809562, 1887883708627582, 15380196764853214, 125893997550676627, 1034945699861044243
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history;
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internal format)
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OFFSET
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0,2
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LINKS
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Table of n, a(n) for n=0..21.
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FORMULA
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a(n) = sum(sum(M(i),i=k..n))^2,k=0..n), where the M(n)'s are the Motzkin numbers.
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MATHEMATICA
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M[n_]:=If[n==0, 1, Coefficient[(1+x+x^2)^(n+1), x^n]/(n+1)]; Table[Sum[Sum[M[i], {i, k, n}]^2, {k, 0, n}], {n, 0, 40}]
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PROG
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(Maxima) M(n):=coeff(expand((1+x+x^2)^(n+1)), x^n)/(n+1);
makelist(sum(sum(M(i), i, k, n)^2, k, 0, n), n, 0, 20);
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CROSSREFS
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Cf. A182013.
Sequence in context: A146178 A272751 A015537 * A291017 A141812 A227206
Adjacent sequences: A182014 A182015 A182016 * A182018 A182019 A182020
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KEYWORD
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nonn
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AUTHOR
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Emanuele Munarini, Apr 06 2012
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STATUS
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approved
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