-1656

Appears in sequences

• sech(exp(x)-sec(x))=1-1/2!*x^2+1/4!*x^4+20/5!*x^5+23/6!*x^6...at n=9A013339
• Convolution of A075298 with A056594.at n=22A075495
• Matrix inverse of triangle A121336, where A121336(n,k) = C( n*(n+1)/2 + n-k + 2, n-k) for n>=k>=0.at n=15A121441
• Inverse binomial transform of A143025, assuming offset zero there.at n=9A173435
• a(n)= +2*a(n-2) +4*a(n-3), n>3.at n=9A173559
• Triangle (read by rows) of coefficients of the polynomials (in ascending order) of the denominators of the generalized sequence of fractions f(n) defined recursively by f(1) = m/1; f(n+1) is chosen so that the sum and the product of the first n terms of the sequence are equal.at n=62A225200
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 157", based on the 5-celled von Neumann neighborhood.at n=21A270332
• Expansion of Product_{k>0} 1/(1 + x^k)^(k*3).at n=17A279031
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f.: Product_{j>0} (1-j^k*x^j)^(1/j).at n=40A294616
• a(n) = 1*2*3*4 - 5*6*7*8 + 9*10*11*12 - 13*14*15*16 + ... - (up to n).at n=7A319544
• a(n) = 4*3*2*1 - 8*7*6*5 + 12*11*10*9 - 16*15*14*13 + ... - (up to the n-th term).at n=7A319887