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1, 1, 8, 512, 262144, 1073741824, 35184372088832, 9223372036854775808, 19342813113834066795298816, 324518553658426726783156020576256, 43556142965880123323311959751266331066368
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refs;
listen;
history;
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internal format)
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OFFSET
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0,3
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COMMENTS
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Sequence given by the Hankel transform (see A001906 for definition) of A082147 = {1, 1, 9, 89, 945, 10577, 123129, 1476841, ...}; example : det([1, 1, 9, 89; 1, 9, 89, 945; 9, 89, 945, 10577; 89, 945, 10577, 123129]) = 8^6 = 262144.
Hankel transform of A059435 = [1, 2, 12, 88, 720, 6304, ...] . - Philippe DELEHAM, Sep 03 2006
The number of labeled graphs (with no self loops) such that at most three edges connect any vertex pair. - Geoffrey Critzer, Nov 10 2011
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LINKS
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Table of n, a(n) for n=0..10.
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FORMULA
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a(n+1) is the determinant of n X n matrix M_(i, j) = binomial(8i, j).
Hankel transform of A059435 = [1, 2, 12, 88, 720, 6304, ...] . - Philippe DELEHAM, Sep 03 2006
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MAPLE
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with(finance):seq(mul(futurevalue( 1, 1, n+k), k=0..n), n=-1..10); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 30 2008
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MATHEMATICA
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Table[2^(3*Binomial[n, 2]), {n, 0, 10}] (* Geoffrey Critzer, Nov 10 2011 *)
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PROG
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(PARI) a(n)=8^binomial(n, 2) \\ Charles R Greathouse IV, Jan 17 2012
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CROSSREFS
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Cf. A006125, A047656, A053763, A053764, A109345, A109354, A109493.
Sequence in context: A145259 A154025 A013713 * A139567 A035131 A067512
Adjacent sequences: A109963 A109964 A109965 * A109967 A109968 A109969
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KEYWORD
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nonn,easy,changed
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AUTHOR
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Philippe DELEHAM, Sep 01 2005
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STATUS
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approved
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