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A073187 Triangle of C(n+1,k)*C(2*n-3*k,n-3*k)/(n+1) by rows. 0
1, 1, 2, 5, 1, 14, 5, 42, 21, 132, 84, 3, 429, 330, 28, 1430, 1287, 180, 4862, 5005, 990, 12, 16796, 19448, 5005, 165, 58786, 75582, 24024, 1430, 208012, 293930, 111384, 10010, 55, 742900, 1144066, 503880, 61880, 1001, 2674440, 4457400, 2238390 (list; table; graph; refs; listen; history; internal format)
OFFSET

1,3

EXAMPLE

1; 1; 2; 5,1; 14,5; 42,21; 132,84,3; 429,330,28; 1430,1287,180; ...

PROG

(PARI) alias(C, binomial); T(n, k)=if(k<0|k>n/3, 0, C(n+1, k)*C(2*n-3*k, n-3*k)/(n+1))

CROSSREFS

Row sums give A071969.

Sequence in context: A101920 A114494 A118964 * A138159 A118919 A101282

Adjacent sequences:  A073184 A073185 A073186 * A073188 A073189 A073190

KEYWORD

nonn,tabl

AUTHOR

Michael Somos, Jul 19 2002

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Last modified February 17 16:33 EST 2012. Contains 206050 sequences.