|
Search: id:A081567
|
|
|
| A081567 |
|
Second binomial transform of F(n+1). |
|
+0 8
|
|
| 1, 3, 10, 35, 125, 450, 1625, 5875, 21250, 76875, 278125, 1006250, 3640625, 13171875, 47656250, 172421875, 623828125, 2257031250, 8166015625, 29544921875, 106894531250, 386748046875, 1399267578125, 5062597656250
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
Binomial transform of A001519. Case k=2 of family of recurrences a(n)=(2k+1)a(n-1)-A028387(k-1)a(n-2), a(0)=1,a(1)=k+1.
Number of (s(0), s(1), ..., s(2n+1)) such that 0 < s(i) < 10 and |s(i) - s(i-1)| = 1 for i = 1,2,....,2n+1, s(0) = 3, s(2n+1) = 4.
a(n+1) gives the number of periodic multiplex juggling sequences of length n with base state <2>. - Steve Butler (sbutler(AT)math.ucsd.edu), Jan 21 2008
|
|
REFERENCES
|
S. Butler and R. Graham, Enumerating (multiplex) juggling sequences, arXiv:0801.2597
|
|
FORMULA
|
a(n)=5a(n-1)-5a(n-2), a(0)=1, a(1)=3. a(n)=(1/2 - sqrt(5)/10)(5/2 - sqrt(5)/2)^n + (sqrt(5)/10 + 1/2)(sqrt(5)/2 + 5/2)^n. G.f.: (1-2x)/(1-5x+5x^2).
a(n-1)=sum(k=1, n, C(n, k)*F(k)^2) - Benoit Cloitre (benoit7848c(AT)orange.fr), Oct 26 2003
a(n)=A090041(n)/2^n - Paul Barry (pbarry(AT)wit.ie), Mar 23 2004
The sequence 0, 1, 3, 10, ... with a(n)=(5/2-sqrt(5)/2)^n/5+(5/2+sqrt(5)/2)^n/5-2(0)^n/5 is the binomial transform of F(n)^2 (A007598) - Paul Barry (pbarry(AT)wit.ie), Apr 27 2004
a(n)=sum{k=0..n, sum{j=0..n, C(n, j)C(j+k, 2k)}}; a(n)=sum{k=0..n, sum{j=0..n, C(n, k+j)*C(k, k-j)2^(n-k-j)}}; a(n)=sum{k=0..n, sum{j=0..n-k, C(n+k-j, n-k-j)C(k, j)(-1)^j*2^(n-k-j)}}; - Paul Barry (pbarry(AT)wit.ie), Nov 15 2005
|
|
CROSSREFS
|
Cf. A000045.
a(n) = 5*A052936(n-1), n>1.
Row sums of A114164.
Sequence in context: A128735 A112107 A094855 this_sequence A026026 A047037 A134391
Adjacent sequences: A081564 A081565 A081566 this_sequence A081568 A081569 A081570
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Paul Barry (pbarry(AT)wit.ie), Mar 22 2003
|
|
|
Search completed in 0.002 seconds
|