20576

Appears in sequences

• Coordination sequence for MgCu2, Mg position.at n=36A009931
• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 71.at n=38A031569
• Number of 'zig-zag' self-avoiding walks on an n X n lattice from a corner to opposite one.at n=8A034165
• Expansion of (1/2)*(1/x^2 - 1/x)*(1-x-sqrt(1-2*x+x^2-4*x^3)) - x.at n=18A052702
• Integers k > 10577 such that the 'Reverse and Add!' trajectory of k joins the trajectory of 10577.at n=7A063434
• Floor of concatenation of n, n+1, n+2, n+3, n+4, n+5 divided by 6.at n=1A074996
• Smallest number such that n*a(n) is a concatenation of n consecutive integers; or 0 if no such number exists.at n=5A075000
• a(n) = floor({concatenation 123 ... up to n}/n).at n=5A077147
• Concatenation of (6n-5), (6n-4), (6n-3), (6n-2), (6n-1) and 6n divided by 6.at n=0A082254
• Smallest k such that k*n is a number that is a permutation of the digits of first n numbers. a(n) = A083429(n)/n.at n=5A083430
• Smallest m such that the decimal representation of the m-th prime interpreted in base n is not a prime, but prime in bases 10 <= b < n.at n=9A091922
• Number of arrangements of 3 nonzero numbers x(i) in -n..n with the sum of trunc(x(i)/x(i+1)) equal to zero.at n=23A189546
• O.g.f.: Sum_{n>=0} 4*(n+4)^(n-1)*x^n/(1+n*x)^n.at n=6A195256
• Principal diagonal of the convolution array A213841.at n=15A213842
• Number of compositions of n into parts 3,4 where both parts are always present.at n=56A245487
• Number of (n+2)X(3+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000011 or 00001111.at n=7A260365
• a(n) = 3*n^3 - 1.at n=19A345701
• Irregular table read by rows: T(n,k) is the number of k-gons, k>=3, formed in a square with edge length 1 by straight line segments when connecting the internal edge points that divide the sides into segments with lengths equal to the Farey series of order n to the equivalent points on the opposite side of the square.at n=35A359656