A065922 Bessel polynomial {y_n}'(4).
0, 1, 27, 846, 32290, 1472535, 78444261, 4789283212, 329976556596, 25336918039005, 2145912573891295, 198763621138900026, 19988975122377164982, 2169175884299414423251, 252661578519463668740745, 31442098485128401965118680, 4163361054820272025075769896
Offset: 0
Keywords
References
- J. Riordan, Combinatorial Identities, Wiley, 1968, p. 77.
Links
Programs
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Mathematica
Table[Sum[(n+k+1)!*2^(k-1)/((n-k-1)!*k!), {k,0,n-1}], {n,0,20}] (* Vaclav Kotesovec, Jul 22 2015 *) RecurrenceTable[{a[0]==0,a[1]==1,a[n]==((2n-1)^3 a[n-1]+n^2 a[n-2])/ (n-1)^2}, a,{n,20}] (* Harvey P. Dale, May 23 2016 *)
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PARI
for(n=0,50, print1(sum(k=0,n-1, (n+k+1)!*2^(k-1)/((n-k-1)!*k!)), ", ")) \\ G. C. Greubel, Aug 14 2017
Formula
Recurrence: (n-1)^2*a(n) = (2*n - 1)^3*a(n-1) + n^2*a(n-2). - Vaclav Kotesovec, Jul 22 2015
a(n) ~ 2^(3*n-3/2) * n^(n+1) / exp(n-1/4). - Vaclav Kotesovec, Jul 22 2015
From G. C. Greubel, Aug 14 2017: (Start)
a(n) = 2*n*(1/2)_{n}*8^(n - 1)* hypergeometric1f1(1 - n, -2*n, 1/2).
E.g.f.: ((1 - 8*x)^(3/2) + 4*x*(1 - 8*x)^(1/2) + 24*x - 1)* exp((1 - sqrt(1 - 8*x))/4)/(16*(1 - 8*x)^(3/2)). (End)
G.f.: (t/(1-t)^3)*hypergeometric2f0(2,3/2; - ; 8*t/(1-t)^2). - G. C. Greubel, Aug 16 2017