43648

Appears in sequences

• Bisection of A002470.at n=22A002287
• A Jacobsthal convolution.at n=17A113726
• 1045*6^n/27-513*2^(n-2)-2072*3^(n-3)+670*(-1)^n*3^(n-3)+254*(-1)^(n+1), n>1.at n=3A121804
• If X_1, ..., X_n is a partition of a 2n-set X into 2-blocks then a(n) is equal to the number of 3-subsets of X containing none of X_i, (i=1,...,n).at n=30A130809
• Irregular triangle read by rows: coefficients of polynomials related to a family of convolutions of certain central binomial sequences.at n=52A142961
• a(n) = ((2+sqrt(5))*(3+sqrt(5))^n + (2-sqrt(5))*(3-sqrt(5))^n)/2.at n=6A162771
• Terms of A181666 of the form 3*k+1.at n=25A172126
• Abundance of A181595(n).at n=36A181596
• Abundance d = sigma(N) - 2*N = A033880(N) of numbers N = A153501(n), i.e., N has d > 0 as divisor.at n=38A182142
• a(1) = 17, a(2) = 80, a(n) = 4*(a(n-1) + a(n-2)) for n >= 3.at n=5A228602
• Number of n X n 0..4 arrays with no element equal to the sum of elements to its left or the sum of the elements above it, modulo 5.at n=2A239187
• Number of nX3 0..4 arrays with no element equal to the sum of elements to its left or the sum of elements above it, modulo 5.at n=2A239189
• T(n,k)=Number of nXk 0..4 arrays with no element equal to the sum of elements to its left or the sum of the elements above it, modulo 5.at n=12A239194
• Numbers k such that lambda(k) = lambda(k+2), where lambda is the Carmichael lambda function (A002322).at n=35A333742
• a(n) is the cardinality of S(n), the subset of partitions of n such that there are enough smaller parts to add together to be greater than a larger part.at n=40A338085
• G.f. A(x) satisfies A(x) = 1 / (1 - x - x * A(x^5)).at n=15A367661