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A068200
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One of a family of sequences that interpolates between the Bell numbers and the factorials.
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3
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1, 2, 6, 24, 120, 696, 4536, 32568, 254136, 2133816, 19130040, 182000952, 1828296888, 19311334200, 213709376184, 2470302259512, 29746381049016, 372270346391352, 4831940144914104, 64925998174811448, 901626111996723384, 12920858504042924856
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refs;
listen;
history;
text;
internal format)
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OFFSET
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0,2
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REFERENCES
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G. Labelle et al., Stirling numbers interpolation using permutations with forbidden subsequences, Discrete Math. 246 (2002), 177-195.
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LINKS
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MAPLE
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g:= proc(n) option remember; `if` (n=0, 1, (1+add(binomial (n-1, k-1) * g(n-k), k=1..n-1)) * 4) end:
a:= n-> `if`(n<=1, n+1, 6*g(n-2)): seq (a(n), n=0..25); # Sean A. Irvine, Feb 02 2024
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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