This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A035049 E.g.f. satisfies A(x) = x(1+A(A(x))), A(0)=0. 3
 1, 2, 12, 144, 2760, 74880, 2676240, 120234240, 6571393920, 426547296000, 32283270835200, 2808028566604800, 277433852555059200, 30836115140589158400, 3824551325912308992000, 525674251444773150720000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Alois P. Heinz, Table of n, a(n) for n = 1..100 FORMULA a(n) = n!*T(n,1), T(n,m) = m/n*sum(k=1..n-m, sum(i=k..n-m, T(n-m,i) * C(i-1,k-1)*(-1)^i)*(-1)^k*C(n+k-1,n-1)), n>m, T(n,n)=1. - Vladimir Kruchinin, May 06 2012 MAPLE A:= proc(n) option remember; local T; if n=0 then 0 else T:= A(n-1); unapply (convert (series (x*(1+T(T(x))), x, n+1), polynom), x) fi end: a:= n-> coeff(A(n)(x), x, n)*n!: seq(a(n), n=1..16); # Alois P. Heinz, Aug 23 2008 MATHEMATICA T[n_, m_] := T[n, m] = If[n == m, 1, m/n*Sum[Sum[T[n-m, i]*Binomial[i-1, k-1]*(-1)^i, {i, k, n-m}]*(-1)^k*Binomial[n+k-1, n-1], {k, 1, n-m}]]; Table[n!*T[n, 1], {n, 1, 16}] (* Jean-François Alcover, Feb 12 2014, after Vladimir Kruchinin *) PROG (Maxima) T(n, m):=if n=m then 1 else m/n*sum(sum(T(n-m, i)*binomial(i-1, k-1)*(-1)^i, i, k, n-m)*(-1)^k*binomial(n+k-1, n-1), k, 1, n-m); makelist(n!*T(n, 1), n, 1, 10); \\ Vladimir Kruchinin, May 06 2012 CROSSREFS Cf. A001028, A030266. Sequence in context: A227462 A262241 A052742 * A010790 A321631 A221101 Adjacent sequences:  A035046 A035047 A035048 * A035050 A035051 A035052 KEYWORD nonn,eigen AUTHOR Christian G. Bower, Oct 15 1998 EXTENSIONS More terms from Alois P. Heinz, Aug 23 2008 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified July 15 22:48 EDT 2019. Contains 325061 sequences. (Running on oeis4.)