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A157335
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Expansion of 1/( (1+x)*(1-7*x+x^2)).
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0
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1, 6, 42, 287, 1968, 13488, 92449, 633654, 4343130, 29768255, 204034656, 1398474336, 9585285697, 65698525542, 450304393098, 3086432226143, 21154721189904, 144996616103184, 993821591532385, 6811754524623510
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| a(n)=A152119(n+1)A152119(n+2).
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LINKS
| Index to sequences with linear recurrences with constant coefficients, signature (6,6,-1)
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FORMULA
| a(n)=sum{k=0..floor(n/2), (-1)^(n-k)*U(k,7/2)} where U(n,x) is the nth-Chebyshev polynomial of the second kind;
a(n)=sum{k=0..2n, F(n+1-floor(k/2))*F(n+1-mod(k,2)-floor(k/2))*A152119(k+1)}.
a(n) = 7*a(n-1) - a(n-2) + (-1)^n, n>1. - Vincenzo Librandi, Mar 13 2011
9*a(n) = 8*A004187(n+1)-A004187(n)+(-1)^n. - R. J. Mathar, Mar 15 2011
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CROSSREFS
| Sequence in context: A074429 A062310 A105482 * A057089 A110711 A156361
Adjacent sequences: A157332 A157333 A157334 * A157336 A157337 A157338
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Feb 27 2009
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