|
Search: id:A102221
|
|
| |
|
| 1, 1, 5, 55, 1077, 32951, 1451723, 87054773, 6818444405, 675900963271, 82717196780955, 12248810651651333, 2158585005685222491, 446445657799551807541, 107087164031952038620481
(list; graph; listen)
|
|
|
OFFSET
|
0,3
|
|
|
FORMULA
|
a(n) = Sum_{k=0..n-1} C(n, k)^2*a(k) for n>0, with a(0)=1. a(n) = A102220(n+k, k)/C(n+k, k)^2 for k>=0.
Sum_{n>=0} a(n)*x^n/n!^2 = 1/(2-BesselI(0,2*sqrt(x))). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Jul 17 2006
|
|
PROGRAM
|
(PARI) a(n)=if(n==0, 1, sum(k=0, n-1, binomial(n, k)^2*a(k)))
|
|
CROSSREFS
|
Cf. A008459, A102220, A102222.
Cf. A000275.
Adjacent sequences: A102218 A102219 A102220 this_sequence A102222 A102223 A102224
Sequence in context: A140049 A130031 A119399 this_sequence A056600 A126456 A126157
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Paul D. Hanna (pauldhanna(AT)juno.com), Dec 31 2004
|
|
|
Search completed in 0.005 seconds
|
