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A062561
a(n) = 3*binomial(2*n, n-1).
1
0, 3, 12, 45, 168, 630, 2376, 9009, 34320, 131274, 503880, 1939938, 7488432, 28973100, 112326480, 436268025, 1697168160, 6611884290, 25792489800, 100734001830, 393847225200, 1541374822260, 6037849200240, 23671113341850
OFFSET
0,2
COMMENTS
a(n) equals 2^(3+2n) times the coefficient of Pi in 2F1(1/2, n+2, 5/2, -1). - John M. Campbell, Jul 17 2011
The array view of A029635 is
2, 2, 2, 2, 2, 2, ...
1, 3, 5, 7, 9, 11, ...
1, 4, 9, 16, 25, 36, ...
1, 5, 14, 30, 55, 91, ...
1, 6, 20, 50, 105, 196, ...
1, 7, 27, 77, 182, 378, ...
and a(n) is the incomplete hook sum Sum_{k=0..n-1} A(n,k) + Sum_{r=0..n-1} A(r,n). - R. J. Mathar, Jun 30 2013
LINKS
MATHEMATICA
Table[3*Binomial[2*n, n-1], {n, 0, 25}]
PROG
(PARI) for(n=0, 22, print(3*binomial(2*n, n-1)))
(PARI) { for (n=0, 200, write("b062561.txt", n, " ", 3*binomial(2*n, n - 1)) ) } \\ Harry J. Smith, Aug 08 2009
(Magma) [3*n*Catalan(n): n in [0..30]]; // Vincenzo Librandi, Jul 19 2011
CROSSREFS
Cf. A001791.
Sequence in context: A258626 A064017 A005320 * A128593 A359813 A085481
KEYWORD
easy,nonn
AUTHOR
Jason Earls, Jul 13 2001
STATUS
approved