283500

Appears in sequences

• Expansion of e.g.f. exp(-x^4/4)/(1-x).at n=9A000138
• Primal codes of canonical finite permutations on positive integers.at n=16A109299
• Triangle T(n,k), the number of permutations on n elements that have no cycles of length k.at n=39A122974
• Triangle read by rows. G(n, k) an additive decomposition of 2^n*G(n), G(n) the Genocchi numbers.at n=41A154344
• Expansion of (1+35*x)/(1-90*x^2).at n=5A182755
• From higher-order arithmetic progressions.at n=4A259459
• Consider coefficients U(m,L,k) defined by the identity Sum_{k=1..L} Sum_{j=0..m} A302971(m,j)/A304042(m,j) * k^j * (T-k)^j = Sum_{k=0..m} (-1)^(m-k) * U(m,L,k) * T^k that holds for all positive integers L,m,T. This sequence gives 4-column table read by rows, where the n-th row lists coefficients U(3,n,k) for k = 0, 1, 2, 3; n >= 1.at n=35A316387
• Expansion of 140*x*(1 + 4*x + x^2) / (1 - x)^5.at n=8A317984
• a(n) = Product_{d|n, d<n} A019565(phi(d)), where phi is the Euler totient function A000010.at n=41A318834
• Numbers with exactly four distinct exponents in their prime factorization, or four distinct parts in their prime signature.at n=24A323025
• a(1) = 1, and for n > 1, a(n) = A276086(n) * a(A064989(n)).at n=34A324889
• Total number of peaks in all permutations of 2 indistinguishable copies of 1..n.at n=4A334776