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A166078
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Expansion of (3(1-x)-sqrt(1+6x-7x^2))/(2(1-x)(1-2x)).
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0
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1, 0, 2, -6, 30, -150, 806, -4494, 25822, -151782, 908502, -5518590, 33933774, -210814422, 1321230150, -8343458286, 53037407166, -339111023046, 2179407749558, -14071216784862, 91225811704750, -593639364476598
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| First column of inverse of Riordan array ((1+x)/(1+x+2x^2),x(1+2x)/(1+x+2x^2)).
Hankel transform is A002416. Binomial transform of A114191.
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REFERENCES
| A. Hora, N. Obata, Quantum Probability and Spectral Analysis of Graphs, Springer, 2007, p. 122
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FORMULA
| G.f.: 1/(1-x+x*c(-2x/(1-x))), c(x) the g.f. of A000108.
G.f.: 1/(1-2x^2/(1-3x-4x^2/(1-3x-4x^2/(1-3x-4x^2/(1-... (continued fraction).
Conjecture: n*a(n) + 2*(2*n-5)*a(n-1) + (34-19*n)*a(n-2) + 14*(n-2)*a(n-3)=0. - R. J. Mathar, Nov 14 2011
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CROSSREFS
| Sequence in context: A055695 A113593 A122763 * A192446 A005432 A009422
Adjacent sequences: A166075 A166076 A166077 * A166079 A166080 A166081
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KEYWORD
| easy,sign
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Oct 06 2009
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