-656

Appears in sequences

• a(n) = Sum_{d|n, d == 1 mod 4} d^2 - Sum_{d|n, d == 3 mod 4} d^2.at n=26A002173
• Numerator of [x^n] in the Taylor expansion exp(cot(x)-coth(x))= 1-2*x/3 +2x^2/9 -4*x^3/81 +2*x^4/243 -136*x^5/25515 +676*x^6/229635 -...at n=7A013551
• a(n) = (1 - (-9)^n)/10.at n=3A014991
• Triangle of q-binomial coefficients for q=-9.at n=11A015121
• Triangle of q-binomial coefficients for q=-9.at n=13A015121
• Gaussian binomial coefficient [ n,3 ] for q = -9.at n=1A015277
• Expansion of q^(-1/2) * (eta(q) * eta(q^2))^4 in powers of q.at n=39A030211
• McKay-Thompson series of class 14b for Monster.at n=57A058506
• Sum_{d divides n} d^2*(-1)^bigomega(d), where bigomega(n) = A001222(n).at n=26A076792
• G.f. A(x) satisfies x = (1 + 4*A(x)) * A(A(x)).at n=5A088675
• Coefficients of the B-Bailey Mod 9 identity.at n=65A104468
• Triangular sequence from the characteristic polynomials of the SL(n,Z)/ determinants {1,-1} type triantidiagonal 2 center with one upper, -1 side antidiagonal above and below: M(3)={{0, -1, 1}, {-1, 2, -1}, {2, -1, 0}}.at n=70A124022
• Triangle of coefficients of a Pascal sum of recursive orthogonal Hermite polynomials given in Hochstadt's book: P(x, n) = x*P(x, n - 1) - n*P(x, n - 2); p2(x,n)=Sum[Binomial[n,m],{m,0,n}].at n=37A136645
• Expansion of q^(-1/2) * (eta(q)^4 * eta(q^4)^2 / eta(q^2)^3)^2 in powers of q.at n=13A138502
• Expansion of ((phi(q) * phi(-q^2)^2)^2 - 1) / 4 in powers of q where phi() is a Ramanujan theta function.at n=26A138505
• Expansion of (phi(-q) / phi(-q^5))^2 in powers of q where phi() is a Ramanujan theta function.at n=35A138518
• Expansion of (8 / 7) * (1 - eta(q)^7 / eta(q^7)) - 7 * (eta(q) * eta(q^7))^3 in powers of q.at n=26A138810
• a(n) = (16-9*8^n)/7.at n=3A165760
• a(n) = (8^n+16*(-9)^n)/17.at n=3A166157
• E.g.f. A(x) = Sum_{n>0} a(n)*x^n/n! is the inverse function to exp(2*x)-x-1.at n=3A205671