OFFSET
0,2
FORMULA
Recurrence:
(n+3)(n+2)(n+1)a(n+2)-4(2n+3)^2(2n+5)(n+1)a(n+1)+16(2n+3)^2(2n+1)^2(n+2)a(n)-144delta(n,0)=0.
MAPLE
a := n -> if n=0 then 1 else binomial(2*n-1, n-1)*(2*n)!/n! fi;
seq(a(n)*sum(1/k, k=1..n+1), n=0..12);
MATHEMATICA
a[n_] := If[n == 0, 1, Binomial[2n - 1, n - 1](2n)!/n!]
Table[a[n]HarmonicNumber[n + 1], {n, 0, 20}]
PROG
(Maxima) a(n):= if n=0 then 1 else binomial(2*n-1, n-1)*(2*n)!/n!;
makelist(a(n)*sum(1/k, k, 1, n+1), n, 0, 12);
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Emanuele Munarini, Mar 11 2011
STATUS
approved