A052392 T(2n+1,n), array T as in A054120.

1, 6, 39, 261, 1779, 12288, 85734, 602871, 4265859, 30338604, 216677490, 1552999242, 11164548078, 80471658192, 581340627372, 4208086875915, 30514467991011, 221620953353844, 1611867544369146

Offset

0,2

Links

Robert Israel, Table of n, a(n) for n = 0..1145

Formula

From Robert Israel, Nov 26 2018: (Start)

Empirical g.f.: (2*x^2-3*x+1)/(2*sqrt(4*x^2-8*x+1)*x)+(x-1)/(2*x).

Empirical recurrence: 8*n*a(n)+(-32-28*n)*a(1+n)+(78+30*n)*a(n+2)+(-45-11*n)*a(n+3)+(5+n)*a(n+4)=0. (End)

Maple

T:= proc(n, k) option remember;
  if k=0 or k=n then return 1 fi;
  if k > n then return 0 fi;
  procname(n-1, k-1) + 2*procname(n-2, k-1) + procname(n-1, k)
end proc;
T(2, 1):= 3:
seq(T(2*n+1, n), n=0..30); # Robert Israel, Nov 26 2018

Crossrefs

Sequence in context: A090018 A238809 A006256 * A370376 A357206 A370026

Adjacent sequences: A052389 A052390 A052391 * A052393 A052394 A052395

Keyword

nonn

Author

Clark Kimberling

Status

approved