-308

Appears in sequences

• a(1) = 0, a(2) = -2; for n > 2, a(n) + a(n-2) - a(n-3) - a(n-5) - ... - a(n-p) = (-1)^(n+1)*n if n is prime, otherwise = 0, where p = largest prime < n.at n=39A002120
• a(1) = 0, a(2) = 0; for n > 2, a(n) - a(n-3) - a(n-5) - ... - a(n-p) = n if n is prime, otherwise = 0, where p = largest prime < n.at n=21A002123
• Discriminants of quadratic number fields Q(sqrt -n) for n squarefree.at n=47A033197
• Revert transform of (x - 1)^2/(1 - x - x^3).at n=8A049133
• a(n) = ceiling(Sum_{k=0..n} tan(k)).at n=33A051510
• Coefficients of the '6th-order' mock theta function 2 mu(q).at n=22A053273
• Matrix inverse of triangle A055290(n+1,k).at n=55A055300
• Column 2 of triangle A055300.at n=10A055301
• McKay-Thompson series of class 40b for Monster.at n=45A058666
• a(n)= Sum_{j=0..floor(n/2)} A073145(2*j + q), where q = 2*(n/2 - floor(n/2)).at n=19A074585
• a(n) = -n^2 - n + 72.at n=19A110678
• Sequence is {a(2,n)}, where a(m,n) is defined at sequence A111518.at n=9A111520
• McKay-Thompson series of class 20C for the Monster group.at n=53A112159
• Bond percolation series for hexagonal net.at n=21A120541
• Triangle read by rows: row n gives coefficients of increasing powers of x in characteristic polynomial of the matrix (-1)^n*M_n, where M_n is the tridiagonal matrix defined in the Comments line.at n=24A124037
• Triangle T(n,k)=binomial(n,k)*A061084(k), 0<=k<=n, read by rows.at n=42A124844
• Triangle read by rows: matrix inverse of A110877.at n=24A126126
• Coefficient table for sums of squares of Chebyshev's S-Polynomials.at n=51A128495
• Coefficient table for sums over product of adjacent Chebyshev S-polynomials.at n=47A128497
• Fourth column (m=3) of triangle A128494.at n=26A128498