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A177452
Partial sums of A002055.
0
1, 10, 66, 366, 1851, 8858, 40890, 184098, 813948, 3549758, 15317294, 65537334, 278489619, 1176688494, 4948173294, 20723897214, 86494746204, 359915608314, 1493718226314, 6184858989714, 25556291840484, 105406847513658
OFFSET
5,2
COMMENTS
Partial sums of number of diagonal dissections of a convex n-gon into n-4 regions. Partial sums of number of standard tableaux of shape (n-4,n-4,1,1). All values shown are nonprime.
FORMULA
a(n) = SUM[i=5..n] A002055(i) = SUM[i=5..n] binomial(i-3, 2)*binomial(2*i-6, i-5)/(i-4).
EXAMPLE
a(9) = 1 + 9 + 56 + 300 + 1485 = 1851 = 3 * 617.
CROSSREFS
Cf. A002055.
Sequence in context: A320817 A004310 A026853 * A033504 A163615 A232062
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, May 09 2010
STATUS
approved