%I #17 Sep 08 2022 08:45:23

%S 0,4,16,49,137,369,978,2574,6754,17699,46355,121379,317796,832024,

%T 2178292,5702869,14930333,39088149,102334134,267914274,701408710,

%U 1836311879,4807526951,12586268999,32951280072,86267571244,225851433688,591286729849,1548008755889

%N a(n) = Fibonacci(2*n) - n - 1.

%C Related to the log base phi of sequence A090162.

%H Vincenzo Librandi, <a href="/A114185/b114185.txt">Table of n, a(n) for n = 2..1000</a>

%H Guo-Niu Han, <a href="/A196265/a196265.pdf">Enumeration of Standard Puzzles</a>, 2011. [Cached copy]

%H Guo-Niu Han, <a href="https://arxiv.org/abs/2006.14070">Enumeration of Standard Puzzles</a>, arXiv:2006.14070 [math.CO], 2020.

%p g:=(-1+3*z)/(1-3*z+z^2): gser:=series(g, z=0, 43): seq(abs(coeff(gser, z, n)-n), n=3..20); # _Zerinvary Lajos_, Mar 22 2009

%t Rest[Table[Fibonacci[2 n] - n - 1, {n, 30}]] (* _Vincenzo Librandi_, Sep 03 2017 *)

%o (Magma) [Fibonacci(2*n)-n-1: n in [2..40]]; // _Vincenzo Librandi_, Sep 03 2017

%Y Cf. A001906, A090162.

%K easy,nonn

%O 2,2

%A _Greg Huber_, Feb 04 2006

%E More terms from _Vincenzo Librandi_, Sep 03 2017