1774080

Appears in sequences

• E.g.f. (1-2x)/(1-2x-x^3).at n=8A052639
• Number of routes of length 2n on the sides of an octagon from a point to opposite point.at n=12A060995
• Number of n step walks (each step +/-1 starting from 0) which are never more than 3 or less than -3.at n=23A068912
• Highly abundant numbers (A002093) that are not Harshad numbers (A005349).at n=18A128702
• Numbers that can be written as (a^2-1)(b^2-1) in three or more distinct ways.at n=16A134856
• Triangle T(n,k), read by rows, given by (2,0,3,0,4,0,5,0,6,0,7,0,8,0,9,...) DELTA (2,1,3,2,4,3,5,4,6,5,7,6,8,7,9,...) where DELTA is the operator defined in A084938.at n=43A199400
• G.f.: Sum_{n>=0} (n-x)^n * x^n / (1 + n*x - x^2)^n.at n=9A202365
• Irregular triangle read by rows: T(n,m) = coefficients in power/Fourier series expansion of an arbitrary anharmonic oscillator's exact period.at n=6A276816
• a(n) = 2^(n-4)*(5*binomial(n,5) + 6*binomial(n,4)).at n=12A384686