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A187547 L(n)H(n+1), product of the central Lah number L(n) and the harmonic number H(n). 8
1, 3, 66, 2500, 134260, 9335088, 796938912, 80671795776, 9446603680800, 1256254443100800, 187033518310129920, 30821040496874234880, 5569495264653352381440, 1095113648992295923200000, 232773183612995427763200000, 53186532693832607435089920000 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
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
Sequence in context: A157543 A368596 A157984 * A157554 A185053 A165655
KEYWORD
nonn,easy
AUTHOR
Emanuele Munarini, Mar 11 2011
STATUS
approved

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Last modified June 15 16:19 EDT 2024. Contains 373407 sequences. (Running on oeis4.)