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A014316
Convolution of Catalan numbers and squares.
1
0, 1, 5, 15, 38, 93, 236, 641, 1869, 5779, 18663, 62179, 211909, 734651, 2581317, 9169247, 32867726, 118729269, 431756336, 1579232417, 5806059402, 21443620901, 79522304354, 295990940421, 1105391706392, 4140688363241, 15553731459744, 58573820469505
OFFSET
0,3
LINKS
FORMULA
a(n) ~ 5 * 2^(2*n+2) / (27 * sqrt(Pi) * n^(3/2)). - Vaclav Kotesovec, Mar 08 2018
G.f.: (1 + x)*(1 - sqrt(1 - 4*x))/(2*(1 - x)^3). - Ilya Gutkovskiy, Mar 21 2018
MAPLE
a:= proc(n) option remember; `if`(n<3, n*(3*n-1)/2,
((60*n^3-232*n^2+264*n-90) *a(n-1)
-(90*n^3-308*n^2+257*n-24) *a(n-2)
+2*(2*n-3)*(10*n^2-12*n+1) *a(n-3))/ (n*(10*n^2-32*n+23)))
end:
seq(a(n), n=0..30); # Alois P. Heinz, Nov 10 2013
MATHEMATICA
a[n_] := Sum[CatalanNumber[k]*(k-n)^2, {k, 0, n}]; Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Mar 16 2017 *)
PROG
(PARI) a(n) = sum(i=0, n, i^2*(2*(n-i))!/((n-i)!*(n-i+1)!)); \\ Michel Marcus, Nov 10 2013
CROSSREFS
Sequence in context: A142964 A050488 A188282 * A075717 A062487 A084447
KEYWORD
nonn
AUTHOR
STATUS
approved