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A034430
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Expand arctan(sqrt(x)*sqrt(x+2))/(sqrt(x)*sqrt(x+2)) and multiply n-th term by 1.3.5...(2n+1).
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4
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1, 2, 7, 36, 249, 2190, 23535, 299880, 4426065, 74294010, 1397669175, 29123671500, 665718201225, 16560190196550, 445300709428575, 12869793995058000, 397815487883438625
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Convolution of A001147 (double factorial numbers) with itself. - DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Mar 21 2005
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FORMULA
| E.g.f.: 1/(1-x)/sqrt(1-2*x). - Vladeta Jovovic (vladeta(AT)eunet.rs), May 11 2003
a(n)=int(x^(2*n+1)*exp(-x^2)*erfi(x/sqrt(2)),x=-infinity..infinity), with erfi the Imaginary Error Function. - Groux Roland, Mar 26 2011
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EXAMPLE
| 1-2*x/3+7*x^2/15-12*x^3/35+83*x^4/315...
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CROSSREFS
| Sequence in context: A167199 A007889 A125033 * A143805 A112293 A090352
Adjacent sequences: A034427 A034428 A034429 * A034431 A034432 A034433
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KEYWORD
| nonn
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AUTHOR
| Jim FitzSimons (cherry(AT)neta.com)
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