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1, 4, 10, 25, 49, 67, 100, 148, 178, 229, 301, 343, 412, 508, 562, 649, 769, 835, 940, 1084, 1162, 1285, 1453, 1543, 1684, 1876, 1978, 2137, 2353, 2467, 2644, 2884, 3010, 3205, 3469, 3607, 3820, 4108, 4258, 4489, 4801, 4963, 5212, 5548, 5722, 5989, 6349, 6535, 6820, 7204, 7402, 7705, 8113, 8323
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,2
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LINKS
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FORMULA
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G.f.: (1 + 3*x + 6*x^2 + 13*x^3 + 18*x^4 + 6*x^5 + 4*x^6 + 3*x^7) / ((1 - x)^3*(1 + x + x^2)^2).
a(n) = a(n-1) + 2*a(n-3) - 2*a(n-4) - a(n-6) + a(n-7) for n>7.
(End)
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MATHEMATICA
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LinearRecurrence[{1, 0, 2, -2, 0, -1, 1}, {1, 4, 10, 25, 49, 67, 100, 148}, 60] (* Harvey P. Dale, Apr 30 2023 *)
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PROG
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(PARI) Vec((1 + 3*x + 6*x^2 + 13*x^3 + 18*x^4 + 6*x^5 + 4*x^6 + 3*x^7) / ((1 - x)^3*(1 + x + x^2)^2) + O(x^50)) \\ Colin Barker, Jan 15 2018
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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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