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FORMULA
| G.f.: [1-z-(z^2-22z+1)^(1/2)]/(10z). a(n) = Sum_{k, 0<=k<=n}A088617(n,k)*5^k . a(n) = Sum_{k, 0<=k<=n} A060693(n,k)*5^(n-k). a(n) = Sum_{k, 0<=k<=n}C(n+k, 2k)5^k*C(k), C(n) given by A000108 .
a(0)=1, a(n)=a(n-1)+5*Sum_{k, 0<=k<=n-1}a(k)*a(n-1-k) . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 23 2007
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