-721

Appears in sequences

• Expansion of log(1+tan(x))*cosh(x).at n=6A009370
• E.g.f.: sech(sin(arctan(x))) (even powers only).at n=3A012029
• sech(arctan(sin(x)))=1-1/2!*x^2+17/4!*x^4-721/6!*x^6+58337/8!*x^8...at n=3A012193
• Expansion of e.g.f.: exp(sin(x)-arctanh(x))=1-3/3!*x^3-23/5!*x^5+90/6!*x^6-721/7!*x^7...at n=7A013388
• exp(arctan(x)-sinh(x))=1-3/3!*x^3+23/5!*x^5+90/6!*x^6-721/7!*x^7...at n=7A013460
• a(n) = 2^n-n^6.at n=3A024016
• Reflected tetranacci numbers A073817.at n=27A074058
• a(n) = -a(n-1) - a(n-2) + a(n-3) - a(n-5).at n=18A089134
• Triangle, read by rows, where T(n,k) = (k/n)*Sum_{d|n} A096797(d,k).at n=69A096798
• Expansion of (1+x+x^2)*(1-8*x^3-14*x^4+8*x^7+x^8)/(1+x^4)^3.at n=38A188477
• a(n) = p(n) - p(n-1) - p(n-2) + p(n-5), where p(n) = A000041(n).at n=30A195054
• G.f.: 1/(1-2*x+2*x^2-x^3+x^4).at n=25A199802
• G.f.: 1/(1 + x - x^2 - x^3 + x^4).at n=26A199803
• Trisection 1 of A199802.at n=8A199928
• Hafnian of a +/-1 array.at n=6A202038
• Triangle T(n, k) = T(n, k-1) + (-1)^k*A060187(n+2,k+1) if k <= floor(n/2), otherwise T(n, n-k), with T(n, 0) = T(n, n) = 1, read by rows.at n=16A225356
• Triangle T(n, k) = T(n, k-1) + (-1)^k*A060187(n+2,k+1) if k <= floor(n/2), otherwise T(n, n-k), with T(n, 0) = T(n, n) = 1, read by rows.at n=19A225356
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of continued fraction 1/(1 + x/(1 - 2^k*x/(1 + 3^k*x/(1 - 4^k*x/(1 + 5^k*x/(1 - ...)))))).at n=34A291207
• a(n) is the smallest error in trying to solve n^4 = x^4 + y^4. That is, for each n from 2 on, find positive integers x and y, x <= y < n such that |n^4 - x^4 - y^4| is minimal and let a(n) = n^4 - x^4 - y^4.at n=11A308834
• a(n) = Sum_{k=1..n} mu(k)*k^4.at n=4A336278