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A152032
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a(n)=3/8+(3/8)*(-1)^n+((n+1)/4)*(-1)^(n+1)+((n+2)*(n+1)/4)*(-1)^(n+2)
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0
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1, -1, 3, -4, 7, -9, 13, -16, 21, -25, 31, -36, 43, -49, 57, -64, 73, -81, 91, -100, 111, -121, 133, -144, 157, -169, 183, -196, 211, -225, 241, -256, 273, -289, 307, -324, 343, -361, 381, -400, 421, -441, 463, -484, 507, -529, 553, -576, 601, -625, 651
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (-2,0,2,1)
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FORMULA
| O.g.f (1+z+z^2)/((1-z)*(1+z)^3) ; a(n+4)=-2*a(n+3)+2*a(n+1)+a(n)
a(n)=(1/8)*[(2*n^2+4*n+5)*(-1)^n+3]. [From Paolo P. Lava (paoloplava(AT)gmail.com), Dec 02 2008]
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CROSSREFS
| Sequence in context: A053099 A073273 A072441 * A004652 A061568 A146994
Adjacent sequences: A152029 A152030 A152031 * A152033 A152034 A152035
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KEYWORD
| sign,easy
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AUTHOR
| Richard Choulet (richardchoulet(AT)wanadoo.fr), Nov 20 2008
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EXTENSIONS
| More terms from 13 ; extended by Richard Choulet (richardchoulet(AT)yahoo.fr) Richard Choulet (richardchoulet(AT)yahoo.fr), Nov 26 2008
Corrected definition. - Paolo P. Lava (paoloplava(AT)gmail.com), Dec 02 2008
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