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A173692
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a(n) = ceiling(A000931(n)/2).
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1
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0, 1, 1, 1, 1, 1, 2, 2, 3, 4, 5, 6, 8, 11, 14, 19, 25, 33, 43, 57, 76, 100, 133, 176, 233, 308, 408, 541, 716, 949, 1257, 1665, 2205, 2921, 3870, 5126, 6791, 8996, 11917, 15786, 20912, 27703, 36698, 48615, 64401, 85313, 113015, 149713, 198328, 262728, 348041, 461056
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history;
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internal format)
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OFFSET
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0,7
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LINKS
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Index entries for linear recurrences with constant coefficients, signature (0,1,1,0,0,0,1,0,-1,-1).
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FORMULA
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a(n) = a(n-2) + a(n-3) + a(n-7) - a(n-9) - a(n-10). - R. J. Mathar, Mar 11 2012
G.f.: x*(1 + x)*(1 - x^3 - x^7) / ((1 - x)*(1 - x^2 - x^3)*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)). - Colin Barker, Feb 26 2020
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MATHEMATICA
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a[0] = 0; a[1] = 1; a[2] = 1;
a[n_] := a[n] = a[n - 2] + a[n - 3]
Table[a[n] - Floor[a[n]/2], {n, 0, 30}]
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PROG
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(PARI) concat(0, Vec(x*(1 + x)*(1 - x^3 - x^7) / ((1 - x)*(1 - x^2 - x^3)*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)) + O(x^40))) \\ Colin Barker, Feb 26 2020
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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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EXTENSIONS
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STATUS
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approved
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