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A071898
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CONTINUANT transform of A002487: 1, 1, 2, 1, 3, 2, ...
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2
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1, 2, 5, 7, 26, 59, 203, 262, 1251, 4015, 21326, 46667, 254661, 810650, 3497261, 4307911, 25036816, 104455175, 756223041, 2373124298, 19741217425, 101079211423, 727295697386, 1555670606195, 11616989940751, 59640620309950, 488741952420351, 1525866477571003
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OFFSET
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1,2
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LINKS
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MAPLE
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b:= proc(n) option remember; `if`(n<2, n,
`if`(irem(n, 2, 'r')=0, b(r), b(r) + b(r+1)))
end:
a:= proc(n) option remember; `if`(n<0, 0,
`if`(n=0, 1, b(n)*a(n-1)+a(n-2)))
end:
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MATHEMATICA
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b[n_] := b[n] = If[n < 2, n, r = Quotient[n, 2]; If[Mod[n, 2] == 0, b[r], b[r] + b[r + 1]]];
a[n_] := a[n] = If[n < 0, 0, If[n == 0, 1, b[n] a[n - 1] + a[n - 2]]];
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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