557056

Appears in sequences

• Denominators of Taylor series expansion of arcsin(x). Also arises from arccos(x), arccsc(x), arcsec(x), arcsinh(x).at n=8A002595
• a(n) = n*(n-1)^4/2.at n=17A019583
• Numbers k such that d(k)^3 divides k.at n=12A046755
• Enumerates pairs consisting of a strongly connected labeled tournament and an arbitrary labeled tournament.at n=4A054947
• a(0)=0, a(1)=1, a(n) = n*2^(n-2) for n >= 2.at n=17A057711
• 16-almost primes (generalization of semiprimes).at n=17A069277
• Numbers k such that phi(k) is a perfect 9th power.at n=17A078169
• Number of n X n circulant singular matrices over GF(2).at n=19A086324
• a(n) = 17*2^n.at n=15A110287
• Numbers n such that A067824(n) = n.at n=28A122408
• Binomial transform of A124625.at n=17A129952
• T(n,k) = numerator of 2*Pi*Sum_{j=0..n-k-1} ((-1)^j*n*(k + j + 2)*(n + k +j)!*(k + j)!^2)/((n - k - j - 1)!*(2*k + j + 1)!*j!*Gamma(k + j + 3/2)*Gamma(k + j + 5/2)), triangle read by rows (n >= 1, 0 <= k <= n - 1).at n=24A159982
• a(n) = n^8*(n^2+1)/2.at n=4A170774
• Number of defective 3-colorings of an n X 2 0..2 array connected horizontally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.at n=8A229580
• a(n) = the number of hills (arch length of 1 with no covering arches) for semi-meander solutions with n arches and floor((n+2)/2) arch group returns to the x axis.at n=32A262258
• Positive solution to 2^(n-1) = (1/n) * Sum_{d|n} a(d) * a(n/d).at n=16A299119
• 2-parking triangle T(r, i, 2) read by rows: T(r, i, k) = (r + 1)^(i-1)*binomial(k*(r + 1) + r - i - 1, r - i) with k = 2 and 0 <= i <= r.at n=33A329058
• Numbers k in A018900 with arithmetic derivative k' (A003415) in A018900.at n=16A357840
• a(n) = (32)^n*cos (nC - nA), where A, B, C are, respectively, the angles opposite sides BC, CA, AB in a triangle ABC having sidelengths |BC| = 2, |CA| = 3, |AB| = 4; ABC is the smallest integer-sided scalene triangle.at n=4A375892
• a(n) = product of {p^k : p | n, k = 1..floor(log n/log p)}, a(1) = 1.at n=33A377486