30380

Appears in sequences

• a(n) = sigma_3(n) - sigma_2(n) - sigma_1(n).at n=29A092350
• Dimensions of the irreducible representations of the simple Lie algebra of type E8 over the complex numbers, listed in increasing order.at n=4A121732
• Number of sequences of length n with elements {-2,-1,+1,+2}, counted up to simultaneous reversal and negation, such that the sum of elements of the whole sequence but of no proper subsequence equals 0 modulo n. For n>=4, the number of Hamiltonian (undirected) cycles on the circulant graph C_n(1,2).at n=26A137726
• A difference triangle of Pascal-Sierpinski 5th level and the Pascal second derivative: a(n,k)= (4*n - 4*k + 1)a(n - 1, k - 1) + (4*k - 3)a(n - 1, k); p(x,n)=(Sum[10*n*(n - 1)*a(n, k)*x^(k - 1) - D[(x + 1)^(n + 2), {x, 2}]/(x + 1), {k, n}])/2.at n=9A155917
• A difference triangle of Pascal-Sierpinski 5th level and the Pascal second derivative: a(n,k)= (4*n - 4*k + 1)a(n - 1, k - 1) + (4*k - 3)a(n - 1, k); p(x,n)=(Sum[10*n*(n - 1)*a(n, k)*x^(k - 1) - D[(x + 1)^(n + 2), {x, 2}]/(x + 1), {k, n}])/2.at n=11A155917
• The number of reachable states in a simple two-player counting game, in which each player starts with the pair (1,1) and one move is to add one of the opponent's numbers to one of your own numbers, but no number can grow above a pre-defined maximum n. The game continues until one of the players has no legal moves left. The winner is the one having the higher sum of his numbers.at n=21A161531
• 5 X 5 X 5 triangular graph without horizontal edges coloring a rectangular array: number of n X 1 0..14 arrays where 0..14 label nodes of a graph with edges 0,1 0,2 1,3 1,4 2,4 2,5 3,6 3,7 4,7 4,8 5,8 5,9 6,10 6,11 7,11 7,12 8,12 8,13 9,13 9,14 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.at n=7A223425
• T(n,k)=5X5X5 triangular graph without horizontal edges coloring a rectangular array: number of nXk 0..14 arrays where 0..14 label nodes of a graph with edges 0,1 0,2 1,3 1,4 2,4 2,5 3,6 3,7 4,7 4,8 5,8 5,9 6,10 6,11 7,11 7,12 8,12 8,13 9,13 9,14 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.at n=28A223432
• Expansion of (3-2*x)/(1-x-x^3)+x/(1-x)^2+x/(1-x^2).at n=27A226509
• Numbers m such that the GCD of the x's that satisfy sigma(x) = m is 4.at n=34A241649
• Partial sums of A147562.at n=44A272928
• Numbers n such that uphi(n) = uphi(n+1), where uphi(n) is the unitary totient function (A047994).at n=32A287055
• Floor of log base n! of product of all primes between n!+1 and (n+1)!.at n=6A294197
• Numbers k such that iphi(k) = iphi(k+1), where iphi(k) is an infinitary analog to the Euler totient function (A091732).at n=28A326403
• Number of subsets of {1..n} not containing their mean.at n=15A327471
• G.f. A(x) = Product_{n>=0} F(n), where F(0) = x, F(1) = 1+x, F(2) = 1 + x*(1+x), and F(n+1) = 1 + (F(n-1) - 1)*(F(n) - 1)*F(n) for n > 1.at n=15A350435
• Numbers k such that A384247(k) = A384247(k+1).at n=39A385743