-211

Appears in sequences

• A sixth-order linear divisibility sequence: a(n+6) = -3*a(n+5) - 5*a(n+4) - 5*a(n+3) - 5*a(n+2) - 3*a(n+1) - a(n).at n=15A005120
• Numerator of the coefficient [x^(2n)] of the Taylor expansion sec(cosec(x)-coth(x))= 1+x^2/72 -211*x^4/31104 +169339*x^6/235146240 -205787*x^8/13544423424+...at n=2A013547
• a(n) = n^2 - primefloor(n)*primeceiling(n).at n=52A056139
• a(n) = n^2 - previousprime(n)*nextprime(n), for n>2.at n=51A056140
• McKay-Thompson series of class 84a for Monster.at n=52A058761
• a(n) = mu(n)*prime(n).at n=46A062007
• a(n) = prime(n)-n*tau(n) where tau(n) is the number of divisors of n.at n=65A067292
• a(n) = prime(n)-n*tau(n) where tau(n) is the number of divisors of n.at n=69A067292
• a(n) = 2^phi(n) - Sum_{j=0..n} binomial(phi(n), phi(j)).at n=15A073318
• Signed primes: if prime(n) even, a(n) = 0; if prime(n) == 1 (mod 4), a(n) = prime(n); if prime(n) == -1 (mod 4), a(n) = -prime(n).at n=46A073579
• a(n) = Sum_{k=0..n} A105595(k)*(-1)^k*A105595(n-k) (interpolated zeros suppressed).at n=20A105596
• Sum(mu(i)*phi(j): i+j=n), with mu=A008683 and phi=A000010.at n=69A112962
• Coefficient table for sums of squares of Chebyshev's S-Polynomials.at n=39A128495
• Triangle read by rows: T(r,c)=T(r,c-1)+T(r,c+1)+T(r-1,c-1).at n=66A129396
• T(n,k) an additive decomposition of the signed tangent number (triangle read by rows).at n=16A154342
• a(n) = Numerator of Bernoulli(n, 1) + 1/(n+1).at n=16A174341
• Numerator in Moebius transform of A001790/A046161.at n=7A180403
• 2n-th derivative of sec(x)^cos(x) at x=0.at n=4A186248
• Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of the symmetric matrix A202674 based on (1,3,5,7,9,...); by antidiagonals.at n=21A202675
• 2n-th derivative of sech(x)^cosh(x) at x=0.at n=4A215677