272160

Appears in sequences

• Expansion of Eisenstein series E_4(q) (alternate convention E_2(q)); theta series of E_8 lattice.at n=10A004009
• Expansion of (1-x)/(1 - 10*x + 18*x^2 - 8*x^3).at n=6A045993
• 6-idempotent numbers.at n=4A050988
• E.g.f. 1/((1-x)(1-x-x^2)).at n=7A052646
• Expansion of e.g.f.: x^3*(exp(x)-1)^3.at n=9A052784
• Leading least prime signatures: a(n) is in A025487 but a(n)/2 is not.at n=35A056153
• Triangle of idempotent numbers binomial(n,k)*k^(n-k), version 2.at n=50A059298
• Triangle of idempotent numbers binomial(n,k)*k^(n-k), version 4.at n=49A059300
• Smallest number whose square has (2n - 1)^2 divisors.at n=16A061708
• a(n) = A062401(A065391(n)): phi(sigma(m)) peak values for numbers m (listed in A065391) at which those peaks are first reached.at n=38A065392
• Numbers k such that k = phi(sigma(phi(sigma(phi(sigma(k)))))).at n=22A067884
• Number of strings of length n over Z_6 with trace 0 and subtrace 1.at n=8A073972
• Number of strings of length n over Z_6 with trace 3 and subtrace 1.at n=8A073990
• Triangle read by rows: T(n,k) is the number of permutations p of [n] in which exactly the first k terms satisfy the up-down property, i.e., p(1)<p(2), p(2)>p(3), p(3)<p(4), ...at n=48A092580
• Triangle read by rows: T(n,k) is the sum of the weights of all vertices labeled k at depth n in the Catalan tree (1 <= k <= n+1, n >= 0).at n=33A102625
• Number of permutations of 5 indistinguishable copies of 1..n arranged in a circle with exactly 1 local maximum.at n=5A159733
• Triangle of z Transform coefficients from General Pascal [1,10,1} A142459 polynomials multiplied by factor 3^Floor[(2*k - 1)/3].at n=25A167787
• Numbers which are the area of exactly three Pythagorean triangles.at n=24A177021
• Number of permutations of 1..n with the sequence of sums of 7 adjacent elements having exactly 1 maximum.at n=3A179731
• Ordered forests of k increasing plane unary-binary trees with n nodes.at n=33A185423