-67
domain: Z
Appears in sequences
- Numerators of coefficients in expansion of sqrt(sin(x)/x) (even powers only).at n=4A008991
- Expansion of e.g.f: (1+x)*cos(x).at n=67A009001
- Expansion of e.g.f. arcsinh(arcsin(x) * exp(x)).at n=5A012322
- Expansion of e.g.f. arcsinh(arcsinh(x) * exp(x)).at n=5A012590
- Discriminants of quadratic number fields Q(sqrt -n) for n squarefree.at n=41A033197
- First differences of sigma(n).at n=47A053222
- Coefficients of the '5th-order' mock theta function f_1(q).at n=79A053257
- Coefficients of the '10th-order' mock theta function X(q).at n=59A053283
- Matrix inverse of triangle A055290(n+1,k).at n=48A055300
- a(n) = n * mu(n), where mu is the Möbius function A008683.at n=66A055615
- Numbers k such that 36*k^2 + 12*k + 7 is prime (sorted by absolute values with negatives before positives).at n=24A056910
- Negate primes in factorization of n.at n=66A061019
- Simple quadratic fields (i.e., with a unique prime factorization).at n=1A061574
- a(n) = mu(n)*prime(n).at n=18A062007
- Multiplicative with a(p^e) = -p.at n=66A062953
- Alternating sum sigma(1)-sigma(2)+sigma(3)-sigma(4)+...+((-1)^(n+1))*sigma(n).at n=20A068762
- 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=18A073579
- Replace 4^k with (-4)^k in base 4 expansion of n.at n=69A073791
- a(n) = A077118(n) - n^3.at n=23A077119
- Expansion of (1-x)^(-1)/(1+2*x^2+x^3).at n=12A077894