1410864

Appears in sequences

• Twice central binomial coefficients.at n=11A028329
• a(n) = Sum_{j=0..n} A047072(j, n-j).at n=23A047073
• Number of n-step walks on a line starting from the origin but not returning to it.at n=23A063886
• A Catalan transform of (1 + 2*x)/(1 - 2*x).at n=11A100320
• Number of n X n (-1,1)-circulant matrices with determinant 0.at n=22A144926
• a(n) = number of n-lettered words in the alphabet {1, 2} with as many occurrences of the substring (consecutive subword) [1, 1] as of [2, 2].at n=24A182027
• Number of arrays of n+2 integers in -1..1 with sum zero and the sum of every adjacent pair being odd.at n=41A202069
• Number of permutations of length n such that numbers at odd positions are monotone and numbers at even positions are also monotone.at n=21A257546
• a(n) = (8*n + 18)*Pochhammer(n, 6) / 6!.at n=12A293614
• Number of tieless quidditch games with n scoring events.at n=22A335974