|
Search: id:A082148
|
|
|
| A082148 |
|
a(0)=1, for n>=1 a(n)=sum(k=0,n,10^k*N(n,k)) where N(n,k) =1/n*C(n,k)*C(n,k+1) are the Narayana numbers (A001263). |
|
+0
6
|
|
| 1, 1, 11, 131, 1661, 22101, 305151, 4335711, 63009881, 932449961, 14004694451, 212944033051, 3271618296661, 50711564152381, 792088104593511, 12454801769554551, 196991734871121201, 3131967533789345361
(list; graph; listen)
|
|
|
OFFSET
|
0,3
|
|
|
COMMENT
|
More generally coefficients of (1+m*x-sqrt(m^2*x^2-(2*m+4)*x+1))/((2*m+2)*x) are given by : a(n)=sum(k=0,n,(m+1)^k*N(n,k))
The Hankel transform of this sequence is 10^C(n+1,2) . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 29 2007
|
|
REFERENCES
|
Paul Barry, On Integer-Sequence-Based Constructions of Generalized Pascal Triangles, Journal of Integer Sequences, Vol. 9 (2006), Article 06.2.4.
|
|
FORMULA
|
G.f. (1+9*x-sqrt(81*x^2-22*x+1))/(20*x)
a(n) = Sum_{k=0..n} A088617(n, k)*10^k*(-9)^(n-k) . - DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Jan 21 2004
a(n) = [11(2n-1)a(n-1) - 81(n-2)a(n-2)] / (n+1) for n>=2, a(0) = a(1) = 1 . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Aug 19 2005
|
|
PROGRAM
|
(PARI) a(n)=if(n<1, 1, sum(k=0, n, 10^k/n*binomial(n, k)*binomial(n, k+1)))
|
|
CROSSREFS
|
Cf. A001003, A007564, A059231.
Sequence in context: A076357 A015606 A077417 this_sequence A075509 A061113 A101334
Adjacent sequences: A082145 A082146 A082147 this_sequence A082149 A082150 A082151
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Benoit Cloitre (benoit7848c(AT)orange.fr), May 10 2003
|
|
|
Search completed in 0.002 seconds
|
