20560

Appears in sequences

• Coordination sequence for {A_4}* lattice.at n=16A008531
• Every run of digits of n in base 4 has length 2.at n=39A033002
• Numbers whose base-4 representation contains exactly four 0's and four 1's.at n=25A045037
• Numbers k such that 2^k - 17 is prime.at n=38A059611
• Solutions to phi(gpf(x)) - gpf(phi(x)) = 254 = c are special multiples of 257, x = 257k, where largest prime factors of factor k were observed from {2, 3, 5, 17}. See solutions to other even cases of c (=A070813): A007283 for 0, A070004 for 2, A070814 for 14, A070816 for 65534.at n=23A070815
• a(n) = A000695(A014486(n)).at n=15A083931
• Difference between the product of two consecutive primes and the next prime.at n=33A111071
• a(n) = Sum_{k=0..n} A109613(k)*A005843(n-k).at n=39A171218
• Number of 4-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and first differences in -n..n.at n=38A208995
• Triangle of coefficients of polynomials u(n,x) jointly generated with A209776; see the Formula section.at n=49A209775
• Number of 0..2 arrays of length n with each element differing from at least one neighbor by 1 or less, starting with 0.at n=10A221677
• Triangle read by rows: T(m,n) is the Szeged index of the grid graph P_m X P_n (1 <= n <= m).at n=48A245826
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 494", based on the 5-celled von Neumann neighborhood.at n=38A272548
• Numbers k such that Bernoulli number B_{k} has denominator 230010.at n=6A295593
• Rectangular array read by downward antidiagonals; row n consists of the numbers m such that n is the denominator of d(k)/d(1) + d(k-1)/d(2) + ... + d(k)/d(1), where d(1),d(2),...,d(k) are the unitary divisors of m.at n=31A305995
• Indices (starting at 0) of integers in the increasing sequence S of nonnegative numbers that are representable in base 3/2 with digits {0, H=1/2, 1}.at n=46A320035
• Expansion of (theta_3(z)*theta_3(23z) + theta_2(z)*theta_2(23z))^5.at n=19A328093
• Triangle T(n,k) read by rows: the number of symmetric binary n X n matrices with k ones and no all-1 2 X 2 submatrix.at n=49A350189
• a(n) is the number of subsets x of Z_n such that #x * #y = n and x + y = Z_n for some subset y of Z_n.at n=26A374770