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A099976 Bisection of A000984. 1
2, 20, 252, 3432, 48620, 705432, 10400600, 155117520, 2333606220, 35345263800, 538257874440, 8233430727600, 126410606437752, 1946939425648112, 30067266499541040, 465428353255261088, 7219428434016265740 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..100

FORMULA

a(n) = binomial(4n+2, 2n+1). - Emeric Deutsch, Dec 20 2004

G.f.: 2*sqrt(2)/sqrt(1-16*x)/sqrt(1+sqrt(1-16*x)) = 2 + 60*x/(G(0)-30*x) where G(k)= 2*x*(4*k+3)*(4*k+5) + (2*k+3)*(k+1)- 2*x*(k+1)*(2*k+3)*(4*k+7)*(4*k+9)/G(k+1); (continued fraction, Euler's 1st kind, 1-step). - Sergei N. Gladkovskii, Jul 14 2012

MAPLE

seq(binomial(4*n+2, 2*n+1), n=0..20); # Emeric Deutsch, Dec 20 2004

PROG

(Magma) [Binomial(4*n+2, 2*n+1): n in [0..20]]; // Vincenzo Librandi, May 22 2011

CROSSREFS

Cf. A000984, A001448.

Sequence in context: A197898 A293471 A109106 * A195157 A207151 A272568

Adjacent sequences: A099973 A099974 A099975 * A099977 A099978 A099979

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Nov 19 2004

EXTENSIONS

More terms from Emeric Deutsch, Dec 20 2004

STATUS

approved

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Last modified February 1 21:03 EST 2023. Contains 359997 sequences. (Running on oeis4.)