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A213770
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Antidiagonal sums of the convolution array A213768.
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3
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1, 7, 23, 58, 126, 250, 467, 837, 1457, 2484, 4172, 6932, 11429, 18739, 30603, 49838, 81002, 131470, 213175, 345425, 559461, 905832, 1466328, 2373288, 3840841, 6215455, 10057727, 16274722, 26334102, 42610594, 68946587, 111559197
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OFFSET
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1,2
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LINKS
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FORMULA
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a(n) = 4*a(n-1) - 5*a(n-2) + a(n-3) + 2*a(n-4) - a(n-5).
G.f.: f(x)/g(x), where f(x) = x*(1 + 3*x) and g(x) = (1 - x - x^2)(1 - x)^3.
a(n) = 2*Fibonacci(n+6) + Lucas(n+4) - n*(2*n + 11) - 23. - Ehren Metcalfe, Jul 08 2019
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MATHEMATICA
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PROG
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(Magma) [2*Fibonacci(n+6)+Lucas(n+4)-n*(2*n+11)-23: n in [1..35]]; // Vincenzo Librandi, Jul 09 2019
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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