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A034270
f(n,n+3) where f is given in A034261.
1
0, 1, 13, 99, 605, 3289, 16653, 80444, 375972, 1715130, 7681586, 33913385, 148018455, 640049865, 2746422525, 11708971560, 49647131160, 209523969630, 880668859590, 3688555690950, 15401089588794, 64128925255626, 266376231244178, 1104047701891624, 4566956385797400
OFFSET
0,3
LINKS
FORMULA
a(n) ~ c*sqrt(n)*4^n, with c = 8/sqrt(Pi) = 2*A249521. - Stefano Spezia, Oct 19 2023
MATHEMATICA
Table[n*(n^2+4*n+1)*Binomial[2*n+3, n]/((n+4)*(n+5)), {n, 0, 20}] (* Vaclav Kotesovec, Oct 27 2012 *)
PROG
(Magma) [n*(n^2+4*n+1)*Binomial(2*n+3, n)/((n+4)*(n+5)): n in [0..25]]; // Vincenzo Librandi, May 04 2013
(PARI) a(n)=n*(n^2+4*n+1)*binomial(2*n+3, n)/((n+4)*(n+5)); \\ Joerg Arndt, May 04 2013
CROSSREFS
KEYWORD
nonn,easy
EXTENSIONS
Corrected and extended by N. J. A. Sloane, Apr 21 2000
STATUS
approved