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A006668
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Exponential self-convolution of Pell numbers (divided by 2).
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3
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0, 0, 1, 6, 32, 160, 784, 3808, 18432, 89088, 430336, 2078208, 10035200, 48455680, 233967616, 1129701376, 5454692352, 26337607680, 127169265664, 614027624448, 2964787822592, 14315262312448, 69120201588736
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,4
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COMMENTS
| Binomial transform of A084150. - Paul Barry (pbarry(AT)wit.ie), May 16 2003
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index to sequences with linear recurrences with constant coefficients, signature (6,-4,-8).
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FORMULA
| a(n)=((2+sqrt(8))^n+(2-sqrt(8))^n-2^(n+1))/16; E.g.f. : exp(2x)(sinh(sqrt(2)x))^2/4=(exp(x)sinh(sqrt(2)x)/sqrt(2))^2/2. - Paul Barry, May 16 2003
G.f.: x^2/((1-2*x)*(1-4*x-4*x^2)). - Bruno Berselli, Aug 20 2011
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PROG
| (MAGMA) [Floor(((2+Sqrt(8))^n+(2-Sqrt(8))^n-2^(n+1))/16): n in [0..30] ]; // Vincenzo Librandi, Aug 20 2011
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CROSSREFS
| Cf. A006646.
Sequence in context: A027217 A121333 A046725 * A037530 A083320 A097139
Adjacent sequences: A006665 A006666 A006667 * A006669 A006670 A006671
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KEYWORD
| nonn,easy
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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