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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

Table of n, a(n) for n=0..15.

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

Cf. A187536, A008297, A111596, A187536, A187538, A187539, A187540, A187542, A187543, A187544, A187545, A187546,  A187548.

Sequence in context: A259457 A157543 A157984 * A157554 A185053 A165655

Adjacent sequences:  A187544 A187545 A187546 * A187548 A187549 A187550

KEYWORD

nonn,easy

AUTHOR

Emanuele Munarini, Mar 11 2011

STATUS

approved

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Last modified April 6 15:23 EDT 2020. Contains 333276 sequences. (Running on oeis4.)