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Revision History for A279881

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A279881

a(n) = A168467(n) * Sum_{k=0..n}(2^k*(k!)^2 / (2*k+1)!).
(history; published version)

#10 by N. J. A. Sloane at Thu Dec 22 23:36:52 EST 2016

STATUS

proposed

approved

#9 by Michael De Vlieger at Thu Dec 22 15:49:04 EST 2016

STATUS

editing

proposed

#8 by Michael De Vlieger at Thu Dec 22 15:49:02 EST 2016

MATHEMATICA

Table[Product[((2 k + 2) (2 k + 3))^(n - k), {k, 0, n}] Sum[(2^j*(j!)^2/(2 j + 1)!), {j, 0, n}], {n, 0, 8}] (* Michael De Vlieger, Dec 22 2016 *)

STATUS

proposed

editing

#7 by Vaclav Kotesovec at Wed Dec 21 17:28:37 EST 2016

STATUS

editing

proposed

#6 by Vaclav Kotesovec at Wed Dec 21 17:25:48 EST 2016

CROSSREFS

Cf. A168467.

STATUS

reviewed

editing

#5 by Vaclav Kotesovec at Wed Dec 21 17:22:10 EST 2016

STATUS

proposed

reviewed

#4 by Daniel Suteu at Wed Dec 21 16:16:44 EST 2016

STATUS

editing

proposed

#3 by Daniel Suteu at Wed Dec 21 16:13:43 EST 2016

LINKS

Daniel Suteu, <a href="/A279881/b279881.txt">Table of n, a(n) for n = 0..19</a>

#2 by Daniel Suteu at Wed Dec 21 16:09:55 EST 2016

NAME

allocated for Daniel Suteu

a(n) = A168467(n) * Sum_{k=0..n}(2^k*(k!)^2 / (2*k+1)!).

DATA

1, 8, 1056, 5529600, 2040024268800, 82038030902231040000, 512596445591262883479552000000, 671373457257855830831011844849664000000000, 238977230623673235057124486022413812190150656000000000000

OFFSET

0,2

FORMULA

a(n) ~ Pi/2 * A168467(n).

a(0) = 1, a(n) = a(n-1) * (2*n + 1)! + 2^n * (n!)^2 * A168467(n-1).

PROG

(PARI) a(n) = prod(k=1, n, (2*k+1)!) * sum(k=0, n, 2^k * (k!)^2 / (2*k+1)!)

KEYWORD

allocated

nonn,easy

AUTHOR

Daniel Suteu, Dec 21 2016

STATUS

approved

editing

#1 by Daniel Suteu at Wed Dec 21 16:09:55 EST 2016

NAME

allocated for Daniel Suteu

KEYWORD

allocated

STATUS

approved