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A052133
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CONTINUANT transform of 0, 1, 1, 2, 1, 3, 2, 3, ... (A002487).
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1
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0, 1, 1, 3, 4, 15, 34, 117, 151, 721, 2314, 12291, 26896, 146771, 467209, 2015607, 2482816, 14429687, 60201564, 435840635, 1367723469, 11377628387, 58255865404, 419168686215, 896593237834, 6695321351053, 34373199993099, 281680921295845, 879415963880634
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OFFSET
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0,4
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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<-1, 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, {q, r} = QuotientRemainder[n, 2]; If[r == 0, b[q], b[q] + b[q+1]]]; a[n_] := a[n] = If[n < -1, 0, If[n < 0, 1, b[n]*a[n-1] + a[n-2]]]; Table[a[n], {n, 0, 35}] (* Jean-François Alcover, Nov 25 2014, after Alois P. Heinz *)
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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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