149226

Appears in sequences

• a(n) = 3*(2*n)!/((n+2)!*(n-1)!).at n=11A000245
• a(n) = 7*binomial(2n,n-3)/(n+4).at n=11A000588
• Even square pyramidal numbers.at n=37A015222
• a(n) = T(n, floor(n/2)), where T = Catalan triangle (A008315).at n=21A026008
• a(n) = n*(n-1)*(n-3)*(n-5).at n=22A062765
• a(n) = 3*binomial(2n, n-1)/(n+2), n > 0, with a(0)=1.at n=11A071724
• Numbers k such that k, 2*k and 4*k are balanced numbers (A020492).at n=26A076376
• Triangle read by rows: T(n,k) is the number of Dyck n-paths whose first descent has length k.at n=66A100537
• Numbers n such that sigma(n) = 12*phi(n).at n=16A104902
• Smallest number that has exactly n distinct prime factors and ends with the digits of n.at n=5A109665
• 9th column of Catalan triangle A009766.at n=6A124087
• Row sums of the inverse of number triangle A(n,k) = 1/C(n) if k <= n <= 2k, 0 otherwise, where C(n) = A000108(n).at n=12A127768
• a(n) = 3*C(4*n-2,2*n)/(2*n+1) - 2*0^n.at n=6A127769
• Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n having k LD's (n>=0; 0<=k<=floor((n-1)/2)).at n=30A128733
• The number of Kekulé structures of the rhombus-shaped benzenoid hydrocarbons.at n=9A130914
• Area ar/6 (divided by 6) of primitive Pythagorean triangles such that perimeters are Averages of twin prime pairs, q=p+1, a=q^2-p^2, c=q^2+p^2, b=2*p*q, ar=a*b/2; s=a+b+c, s-+1 are primes.at n=10A155177
• Triangle read by rows: T(n,k) = (4k+3)/(n+2k+2)*binomial(2n,n+2k+1).at n=31A158483
• Triangle read by rows: T(n,k) = (4k+3)/(n+2k+2)*binomial(2n,n+2k+1).at n=32A158483
• Number of ballot sequences of length n having 8 largest parts.at n=14A244105
• Number of ballot sequences of length n having 10 largest parts.at n=12A244107