135135

Appears in sequences

• Double factorial of odd numbers: a(n) = (2*n-1)!! = 1*3*5*...*(2*n-1).at n=7A001147
• Triangle of coefficients of Bessel polynomials (exponents in decreasing order).at n=29A001497
• Triangle of coefficients of Bessel polynomials (exponents in decreasing order).at n=28A001497
• Triangle of coefficients of Bessel polynomials (exponents in decreasing order).at n=50A001497
• Triangle a(n,k) (n >= 0, 0 <= k <= n) of coefficients of Bessel polynomials y_n(x) (exponents in increasing order).at n=35A001498
• Triangle a(n,k) (n >= 0, 0 <= k <= n) of coefficients of Bessel polynomials y_n(x) (exponents in increasing order).at n=49A001498
• Triangle a(n,k) (n >= 0, 0 <= k <= n) of coefficients of Bessel polynomials y_n(x) (exponents in increasing order).at n=34A001498
• Coefficients of Bessel polynomials y_n (x).at n=4A001881
• Double factorials n!!: a(n) = n*a(n-2) for n > 1, a(0) = a(1) = 1.at n=13A006882
• Triangle of numbers arising from analysis of Levine's sequence A011784.at n=42A014621
• Triangle of coefficients in expansion of (x+1)*(x+3)*...*(x + 2n - 1) in rising powers of x.at n=28A028338
• Lucky numbers that are concatenations of a number k with itself.at n=17A032650
• The convolution matrix of the double factorial of odd numbers (A001147).at n=21A035342
• Triangular table of 2^n *(n+k)! / ((n-k)! * k! * 4^k).at n=35A043302
• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= n/2.at n=28A047170
• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n-1)/2.at n=28A047181
• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= n/3.at n=39A048002
• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n-1)/3.at n=39A048015
• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n+1)/3.at n=39A048048
• Triangle giving a(n,k) = number of (n,k) labeled Greg trees (n >= 2, 0 <= k <= n-2).at n=35A048159