28600

Appears in sequences

• G.f.: 1/((1-x)*(1-x^2))^5.at n=12A038165
• Numbers k such that sopfr(k) = sopfr(k - sopfr(k)).at n=29A050781
• Expansion of (1+10*x+5*x^2)/(1-x)^10.at n=6A059601
• Numbers n such that { x +- 2^k : 0 < k < 4 } are primes, where x = 210*n - 105.at n=11A061671
• Numbers k such that (1_666.2_666.3_666 ... 8_666.9_666)*10^k + 1 is prime, i.e., 1 repeated 666 times, concatenated with 2 repeated 666 times, etc.at n=7A106488
• Sum of numbers under a triangle on a spiral staircase of width 10.at n=23A111080
• T(n,k) = Sum_{i=0..k} (-1)^(k-i)*binomial(k,i)*A000670(n-k+i).at n=33A122101
• Floor of sum of the first n^2 square roots.at n=35A138357
• Triangle read by rows: T(n,k) is the number of permutations of n elements with transposition distance equal to k, n >= 1 and 0 <= k <= A065603(n).at n=52A164366
• Number of (w,x,y,z) with all terms in {0,...,n} and 2w-x=max{w,x,y,z}-min{w,x,y,z}.at n=38A212756
• Number of (n+2)X(2+2) nonnegative integer arrays with all values the knight distance from the upper left minus as much as 2, with successive minimum path knight move differences either 0 or +1, and any unreachable value zero.at n=3A253113
• Number of (n+2)X(4+2) nonnegative integer arrays with all values the knight distance from the upper left minus as much as 2, with successive minimum path knight move differences either 0 or +1, and any unreachable value zero.at n=1A253115
• T(n,k)=Number of (n+2)X(k+2) nonnegative integer arrays with all values the knight distance from the upper left minus as much as 2, with successive minimum path knight move differences either 0 or +1, and any unreachable value zero.at n=11A253119
• T(n,k)=Number of (n+2)X(k+2) nonnegative integer arrays with all values the knight distance from the upper left minus as much as 2, with successive minimum path knight move differences either 0 or +1, and any unreachable value zero.at n=13A253119
• Numbers k such that (68*10^k + 7)/3 is prime.at n=30A270613
• Total volume of the family of rectangular prisms with dimensions p, q and p + q where p divides q, n = p + q and p < q.at n=43A303481
• a(n) = denominator of Sum_{1 <= i < j <= d(n)} 1/(d_j - d_i), sum over ordered pairs of divisors of n, where d(n) is the number of divisors of n.at n=25A330078
• Numbers with an equal number of deficient and abundant divisors.at n=36A335543
• a(n) is the least positive integer divisible by exactly n primitive nondeficient numbers (A006039).at n=7A337691
• Number of ways to write n as an ordered sum of 5 squarefree numbers.at n=43A341065