-13

Appears in sequences

• Canonical enumeration of integers: interleaved positive and negative integers with zero prepended.at n=26A001057
• The negative integers.at n=12A001478
• a(n) = -n.at n=13A001489
• Generalized sum of divisors function: excess of sum of odd divisors of n over sum of even divisors of n.at n=7A002129
• Generalized sum of divisors function: excess of sum of odd divisors of n over sum of even divisors of n.at n=17A002129
• Glaisher's chi numbers. a(n) = chi(4*n + 1).at n=72A002171
• a(n) = a(n-1) - 2*a(n-2) with a(0) = 2, a(1) = 1.at n=7A002249
• Coefficients in the expansion of B^2*C^3 in Watson's notation of page 118.at n=23A002300
• Numerators of coefficients in asymptotic expansion of (2/Pi)*Integral_{0..oo} (sin x / x)^n dx.at n=2A002304
• Coefficients of modular function G_3(tau).at n=4A005761
• Coefficients of modular function denoted G_6(tau) by Atkin.at n=2A005764
• From fundamental unit of Z[ (-d)^{1/4} ], where d runs over positive integers not of the form 4*k^4.at n=12A006828
• From fundamental unit of Z[ (-n)^{1/4} ].at n=24A006831
• Moebius transform applied thrice to natural numbers.at n=49A007432
• Reversion of g.f. for Fibonacci numbers 1, 1, 2, 3, 5, ....at n=8A007440
• Unique attractor for (RIGHT then MOBIUS) transform.at n=38A007554
• Expansion of Product_{k>=1} (1 - x^k)^13.at n=1A010820
• sech(sin(sinh(x)))=1-1/2!*x^2+5/4!*x^4-13/6!*x^6-407/8!*x^8...at n=3A012033
• sech(tan(tanh(x)))=1-1/2!*x^2+5/4!*x^4-13/6!*x^6-1751/8!*x^8...at n=3A012173
• E.g.f.: sin(sin(x)+log(x+1))=2*x-1/2!*x^2-7/3!*x^3+18/4!*x^4-13/5!*x^5...at n=5A012888