30450

Appears in sequences

• a(n) = n*(n+1)*(4*n+5)/6.at n=35A016061
• Theta series of A*_14 lattice.at n=33A023926
• Numbers k such that n | sigma_10(k) + phi(k)^10.at n=16A055704
• z-value of the solution (x,y,z) to 5/n = 1/x + 1/y + 1/z satisfying 0 < x < y < z and having the largest z-value. The x and y components are in A075249 and A075250.at n=26A075251
• Numbers n divisible by exactly two nontrivial permutations (rearrangements) of the digits of n.at n=29A090057
• a(n) = n*(n+1)*(8*n + 1)/6.at n=28A132124
• Column l=4 of irregular triangle in A133709.at n=5A133711
• Integers that do not have a partition into a sum of an odd square and two (not necessarily distinct) triangular numbers.at n=45A191764
• a(n) = n*(3*n^2 + 6*n + 1).at n=21A196507
• Sum_{0<j<k<=n} s(k)-s(j), where s(j)=A002620(j) is the j-th quarter-square.at n=27A206806
• Number of (w,x,y,z) with all terms in {1,...,n} and w>2x and y>=3z.at n=30A212519
• Number of length 3 1..(n+1) arrays with every leading partial sum divisible by 2, 3 or 5.at n=41A254830
• Least positive integer k such that prime(k)-k, prime(k)+k, prime(k*n)-k*n, prime(k*n)+k*n, prime(k)+k*n and prime(k*n)+k are all prime.at n=47A259492
• Unitary practical numbers that are nonsquarefree.at n=21A287173
• 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 3-column table read by rows, where the n-th row lists coefficients U(2,n,k) for k = 0, 1, 2; n >= 1.at n=41A316349
• Expansion of 30*x*(1 + x) / (1 - x)^4.at n=13A316459
• Sums of three primorials > 1.at n=44A370137
• Semiperimeter of the unique primitive Pythagorean triple whose inradius is the n-th odd prime and whose short leg is an even number.at n=38A380301
• E.g.f. A(x) satisfies A(x) = 1 + x^3*exp(x)*A(x)^3.at n=7A390649