%I A054851
%S A054851 1,16,144,960,5280,25344,109824,439296,1647360,5857280,19914752,
%T A054851 65175552,206389248,635043840,1905131520,5588385792,16066609152,
%U A054851 45364543488,126012620800,344876646400,931166945280,2483111854080
%N A054851 2^(n-7)*C(n,7). Number of 7D hypercubes in an n-dimensional hypercube.
%C A054851 If X_1,X_2,...,X_n is a partition of a 2n-set X into 2-blocks then, for
n>6, a(n) is equal to the number of (n+7)-subsets of X intersecting
each X_i (i=1,2,...,n). - Milan R. Janjic (agnus(AT)blic.net), Jul
21 2007
%C A054851 With a different offset, number of n-permutations (n>=7) of 3 objects:
u,v,z with repetition allowed, containing exactly seven (7) u's.
Example: a(1)=16 because we have uuuuuuuv, uuuuuuvu, uuuuuvuu, uuuuvuuu,
uuuvuuuu, uuvuuuuu, uvuuuuuu, vuuuuuuu, uuuuuuuz, uuuuuuzu, uuuuuzuu,
uuuuzuuu, uuuzuuuu, uuzuuuuu, uzuuuuuu and zuuuuuuu. - Zerinvary
Lajos (zerinvarylajos(AT)yahoo.com), Jun 23 2008
%H A054851 Milan Janjic, <a href="http://www.pmfbl.org/janjic/">Two Enumerative
Functions</a>
%F A054851 a(n)=2*a(n-1)+A002409(n-1)
%p A054851 seq(binomial(n+7,7)*2^n,n=0..21); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com),
Jun 23 2008
%o A054851 (Other) SAGE: [lucas_number2(n, 2, 0)*binomial(n,7)/128 for n in xrange(7,
29)] [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Mar 10
2009]
%Y A054851 Cf. A000079, A001787, A001788, A001789, A003472, A054849, A002409, A038207.
%Y A054851 a(n+8) = A082141(n+1)/2.
%Y A054851 Sequence in context: A060300 A128985 A004409 this_sequence A000762 A086952
A155663
%Y A054851 Adjacent sequences: A054848 A054849 A054850 this_sequence A054852 A054853
A054854
%K A054851 easy,nonn
%O A054851 7,2
%A A054851 Henry Bottomley (se16(AT)btinternet.com), Apr 14 2000
%E A054851 More terms from James A. Sellers (sellersj(AT)math.psu.edu), Apr 15 2000
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