A028283 - OEIS

%I #20 Jun 05 2021 06:03:22

%S 1,4,10,32,110,392,1428,5280,19734,74360,281996,1074944,4115020,

%T 15808912,60917800,235350720,911315430,3535767000,13742347740,

%U 53495534400,208537056420,813950932080,3180614712600,12441628655040

%N Central elements in 4-Pascal triangle A028275 (by row).

%C Equals A000984, [1, 2, 6, 20, 70, ...] convolved with [1, 2, 0, 0, 0, ...]. - _Gary W. Adamson_, Jun 05 2009

%F a(n) = 2*A051960(n-1).

%F a(n) = 2*A000108(n)*(3n-1). - _Ralf Stephan_, Aug 24 2003

%Y Cf. A000108, A028275, A051960.

%K nonn,easy

%O 0,2

%A _Mohammad K. Azarian_