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A103780
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Row sums of square of trinomial triangle A071675.
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0
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1, 1, 3, 9, 25, 69, 189, 519, 1428, 3930, 10812, 29742, 81816, 225070, 619156, 1703262, 4685565, 12889687, 35458707, 97544655, 268339161, 738183999, 2030697309, 5586319365, 15367609920, 42275319276, 116296719448
(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 (1,2,4,6,8,8,6,3,1).
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FORMULA
| G.f.: 1/(1-x-2x^2-4x^3-6x^4-8x^5-8x^6-6x^7-3x^8-x^9).
a(n)=a(n-1)+2a(n-2)+4a(n-3)+6a(n-4)+8a(n-5)+8a(n-6)+6a(n-7)+3a(n-8)+a(n-9).
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PROG
| (Maxima)
a(n):=sum(sum((sum(binomial(j, n-3*k+2*j)*(-1)^(j-k)*binomial(k, j), j, 0, k)) *sum(binomial(j, -3*m+k+2*j)*binomial(m, j), j, 0, m), k, m, n), m, 0, n); [From Vladimir Kruchinin, Dec 01 2011].
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CROSSREFS
| Sequence in context: A000242 A077846 A005322 * A206727 A098182 A007046
Adjacent sequences: A103777 A103778 A103779 * A103781 A103782 A103783
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Feb 15 2005
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