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A014151
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Apply partial sum operator thrice to Catalan numbers.
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3
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1, 4, 11, 27, 66, 170, 471, 1398, 4381, 14282, 47897, 164012, 570639, 2010678, 7158569, 25709157, 93020112, 338736224, 1240496193, 4565563209, 16878057692, 62644246662, 233346693759, 872045012633, 3268643350608, 12285088109136, 46288732360369, 174813127020311, 661606223839322
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OFFSET
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0,2
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LINKS
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FORMULA
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D-finite with recurrence: n*(n+1)*a(n) = 2*n*(3*n+1)*a(n-1) - (9*n^2+7*n-4)*a(n-2) + 2*(n+1)*(2*n+1)*a(n-3). - Vaclav Kotesovec, Oct 07 2012
G.f.: C(x)/(1-x)^3, where C(x) is g.f. of Catalan numbers. - Vladimir Kruchinin, Oct 18 2016
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MATHEMATICA
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Flatten[{1, RecurrenceTable[{n*(n+1)*a[n] == 2*n*(3*n+1)*a[n-1] - (9*n^2+7*n-4)*a[n-2] + 2*(n+1)*(2*n+1)*a[n-3], a[1]==4, a[2]==11, a[3]==27}, a, {n, 100}]}]
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PROG
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(PARI)
sm(v)={my(s=vector(#v)); s[1]=v[1]; for(n=2, #v, s[n]=v[n]+s[n-1]); s; }
C(n)=binomial(2*n, n)/(n+1);
sm(sm(sm(vector(66, n, C(n-1)))))
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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