17990

Appears in sequences

• Weird numbers: abundant (A005101) but not pseudoperfect (A005835).at n=29A006037
• Number of strict first-order maximal independent sets in path graph.at n=34A007383
• Define the generalized Pisot sequence T(a(0),a(1)) by: a(n+2) is the greatest integer such that a(n+2)/a(n+1) < a(n+1)/a(n). This is T(3,6).at n=15A018918
• Pisot sequences E(6,8), P(6,8).at n=28A020716
• Dying rabbits: a(n) = a(n-1) + a(n-2) - a(n-4).at n=34A023434
• a(n) = [ (3rd elementary symmetric function of S(n))/(first elementary symmetric function of S(n)) ], where S(n) = {first n+2 positive integers congruent to 1 mod 3}.at n=13A024220
• Unitary weird numbers: unitary abundant (A034683) but not unitary pseudoperfect (A293188).at n=26A064114
• Expansion of 1/((1-2*x+x^2-x^3)*(1-x)).at n=16A077855
• a(n) = sigma[k](n) - phi(n)^k - d(n)^k for k=3.at n=25A079539
• a(n) = A000931(n+4) - A010060(n).at n=37A140514
• Triangle read by rows: expansion of p(x,n)=If[n == 0, 1, (x + 1)^n + 2^(n - 1)*Sum[Binomial[n, m]*x^m*(1 + x^(n - 2*m)), {m, 1, n - 1}]].at n=40A146765
• Number of compositions of n into parts 2 and 3 with at least one 2 and one 3.at n=38A245332
• Expansion of phi(-x^6) / f(-x) in powers of x where phi(), f() are Ramanujan theta functions.at n=42A271661
• Bi-unitary weird numbers: bi-unitary abundant numbers (A292982) that are not bi-unitary pseudoperfect (A292985).at n=31A292986
• Numbers k such that Bernoulli number B_{k} has denominator 4686.at n=12A295770
• Infinitary weird numbers: infinitary abundant numbers (A129656) that are not infinitary pseudoperfect numbers (A306983).at n=32A306984
• Triangle read by rows: coefficients of expansion of certain weighted sums P_1(n,k) of Fibonacci numbers as a sum of powers.at n=40A341723
• Nonexponential weird numbers: nonexponential abundant numbers (A348604) that are not equal to the sum of any subset of their nonexponential divisors.at n=23A348631
• First differences of A307632.at n=33A348773
• a(n) = A348773(2*n).at n=16A348775