-19

Appears in sequences

• Let A(n) = #{(i,j): i^2 + j^2 <= n}, V(n) = Pi*n, P(n) = A(n) - V(n); A000099 gives values of n where |P(n)| sets a new record; sequence gives closest integer to P(A000099(n)).at n=17A000036
• Canonical enumeration of integers: interleaved positive and negative integers with zero prepended.at n=38A001057
• The negative integers.at n=18A001478
• a(n) = -n.at n=19A001489
• 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=18A002120
• Numerators of logarithmic numbers (also of Gregory coefficients G(n)).at n=4A002206
• Expansion of a modular function for Gamma_0(14).at n=5A002509
• Expansion of tan(x /cosh(x)).at n=2A003700
• Power series expansion of the Rogers-Ramanujan continued fraction 1+x/(1+x^2/(1+x^3/(1+x^4/(1+...)))).at n=59A003823
• 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=10A005120
• Numerators of Cauchy numbers of first type.at n=4A006232
• Numerators of sequence having sqrt(cos(x)) as e.g.f. (even-indexed coefficients only).at n=3A008990
• Expansion of e.g.f: (1+x)*cos(x).at n=19A009001
• Expansion of e.g.f. cos(sin(x)*exp(x)).at n=4A009048
• Expansion of e.g.f. cos(tan(x)*cosh(x)), even terms only.at n=2A009075
• E.g.f. is cos(tan(x)/cos(x)), coefficients of even powers of x.at n=2A009081
• Expansion of exp(tanh(x)*cos(x)).at n=4A009267
• Expansion of exp(tanh(x)/cosh(x)).at n=4A009275
• Expansion of e.g.f. exp(x)*cosh(log(1+x)).at n=5A009281
• E.g.f. log(1+log(1+tanh(x))).at n=4A009311