A177452 Partial sums of A002055.

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.

Links

Table of n, a(n) for n=5..26.

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

Adjacent sequences: A177449 A177450 A177451 * A177453 A177454 A177455

Keyword

nonn

Author

Jonathan Vos Post, May 09 2010

Status

approved