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 A230585 First terms of first rows of zigzag matrices as defined in A088961. 2
 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 (list; graph; refs; listen; history; text; internal format)
 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: A052974 A284415 A318227 * A006395 A078718 A081393 Adjacent sequences:  A230582 A230583 A230584 * A230586 A230587 A230588 KEYWORD nonn AUTHOR Reinhard Zumkeller, Oct 25 2013 STATUS approved

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Last modified December 4 21:30 EST 2020. Contains 338939 sequences. (Running on oeis4.)