OFFSET
1,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..200
Paul Barry, Generalized Catalan Numbers Associated with a Family of Pascal-like Triangles, J. Int. Seq., Vol. 22 (2019), Article 19.5.8.
FORMULA
a(n) = Sum_{m=2..2*n} A090452(n, m).
Recurrence: (n+1)*a(n) = 6*(2*n-1)*a(n-1) - 4*(n-2)*a(n-2). - Vaclav Kotesovec, Oct 14 2012
a(n) ~ sqrt(4+3*sqrt(2))*(6+4*sqrt(2))^n/(8*sqrt(Pi)*n^(3/2)). - Vaclav Kotesovec, Oct 14 2012
MATHEMATICA
RecurrenceTable[{(n+1)*a[n] == 6*(2*n-1)*a[n-1] - 4*(n-2)*a[n-2], a[1]==1, a[2]==6}, a, {n, 20}] (* Vaclav Kotesovec, Oct 14 2012 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Dec 23 2003
STATUS
approved