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A242323
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Number of binary words of length n that contain all 32 5-bit words as (possibly overlapping) contiguous subwords.
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4
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65536, 352256, 1442816, 5313536, 18323520, 60481632, 192562808, 593792608, 1782459992, 5221699004, 14967607810, 42060446246, 116067269324
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OFFSET
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36,1
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LINKS
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EXAMPLE
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a(36) = 65536: 000001000110010100111010110111110000, ... .
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MAPLE
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b:= proc(n, t, s) option remember; `if`(s={}, 2^n,
`if`(nops(s)>n, 0, b(n-1, irem(2*t, 16), s minus {2*t})
+b(n-1, irem(2*t+1, 16), s minus {2*t+1})))
end:
a:= n-> add(b(n-4, j, {$0..31}), j=0..15):
seq(a(n), n=36..37);
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MATHEMATICA
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b[n_, t_, s_] := b[n, t, s] = If[s == {}, 2^n,
If[Length[s] > n, 0, b[n-1, Mod[2*t, 16], s~Complement~{2*t}] +
b[n-1, Mod[2*t+1, 16], s~Complement~{2*t+1}]]];
a[n_] := Sum[b[n-4, j, Range[0, 31]], {j, 0, 15}];
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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