A230585 First terms of first rows of zigzag matrices as defined in A088961.

3, 5, 14, 42, 132, 429, 1430, 4862, 16796, 58786, 208012, 742900, 2674440, 9694845, 35357670, 129644790, 477638700, 1767263190, 6564120420, 24466267020, 91482563640, 343059613650, 1289904147324, 4861946401452, 18367353072152, 69533550916004, 263747951750360

Offset

1,1

Comments

a(n) = A088961(A056520(n-1));

a(n) = A000108(n+1) for n > 1.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Formula

a(n) = binomial(2*n,n) - binomial(2*n,n+2) + 0^(n-1).

Prog

(Haskell)
a230585 1 = 3
a230585 n = a007318 (2*n) n - a007318 (2*n) (n+2)

Crossrefs

Cf. A007318.

Sequence in context: A284415 A318227 A363542 * A006395 A078718 A081393

Adjacent sequences: A230582 A230583 A230584 * A230586 A230587 A230588

Keyword

nonn

Author

Reinhard Zumkeller, Oct 25 2013

Status

approved