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 A050262 G.f.: ( 1 + x + x^2 - x^3 - x^4 - sqrt( 1 - 2 x - 5 x^2 - 4 x^3 - 3 x^4 - 4 x^5 - x^6 + 2 x^7 + x^8 ) ) / ( 2 x (1 + x) ). 1

%I

%S 1,1,1,4,10,27,79,238,736,2322,7445,24190,79470,263534,880966,2965576,

%T 10044096,34202268,117026156,402139968,1387243056,4802307553,

%U 16677543678,58087052893,202855613896,710171007580,2491870287323

%N G.f.: ( 1 + x + x^2 - x^3 - x^4 - sqrt( 1 - 2 x - 5 x^2 - 4 x^3 - 3 x^4 - 4 x^5 - x^6 + 2 x^7 + x^8 ) ) / ( 2 x (1 + x) ).

%H Robert Israel, <a href="/A050262/b050262.txt">Table of n, a(n) for n = 0..1761</a>

%F (n-2)*a(n) + (-3+3*n)*a(1+n) + (n-2)*a(n+2) + (-11-5*n)*a(3+n) + (-22-7*n)*a(n+4) + (-34-7*n)*a(n+5) + (-57-9*n)*a(n+6) + (-52-7*n)*a(n+7) + (-7-n)*a(n+8) + (10+n)*a(n+9) = 0. - _Robert Israel_, Jan 15 2018

%p f:= gfun:-rectoproc({(n-2)*a(n)+(-3+3*n)*a(1+n)+(n-2)*a(n+2)+(-11-5*n)*a(3+n)+(-22-7*n)*a(n+4)+(-34-7*n)*a(n+5)+(-57-9*n)*a(n+6)+(-52-7*n)*a(n+7)+(-7-n)*a(n+8)+(10+n)*a(n+9), a(0) = 1, a(1) = 1, a(2) = 1, a(3) = 4, a(4) = 10, a(5) = 27, a(6) = 79, a(7) = 238, a(8) = 736}, a(n), remember):

%p map(f, [\$0..50]); # _Robert Israel_, Jan 15 2018

%K easy,nonn

%O 0,4

%A _Emanuele Munarini_, May 09 2003

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Last modified May 19 12:59 EDT 2019. Contains 323393 sequences. (Running on oeis4.)