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A303587
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Number of partitions of n that contain exactly one isolated singleton.
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2
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0, 1, 0, 1, 1, 3, 5, 12, 24, 56, 123, 292, 682, 1667, 4079, 10288, 26159, 68026, 178823, 478659, 1296271, 3564911, 9919320, 27978084, 79816424, 230520511, 673071482, 1987599262, 5930739339, 17883932293, 54464027956, 167512285647, 520076498672, 1629804156975
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OFFSET
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1,6
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LINKS
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MAPLE
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f:=proc(n, r) local j;
add(combinat:-bell(j-1)*binomial(n-j-1, j-r-1), j=1..floor((n+r)/2));
end;
[seq(f(n, 1), n=1..40)];
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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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