31050

Appears in sequences

• Triangle of "Harmonic Coefficients" T(n,k), read by rows: (Sum_{i=1..n} T(n,i) * k^i) * k! / ((n+k)! * n!) = (Sum_{i=1..k} (1/i-1/(i+n)) = n * (Sum_{i=1..k} 1/(i*(i+n)))).at n=11A027858
• Sum of three solutions of the Diophantine equation x^2 - y^2 = z^3.at n=15A085409
• Numbers k divisible by at least one nontrivial permutation (rearrangement) of the digits of k, excluding all permutations that result in digit loss.at n=8A090056
• Numbers n divisible by exactly four nontrivial permutations (rearrangements) of the digits of n.at n=0A090059
• Number of partitions of n in which no parts are multiples of 25.at n=39A092885
• Consider a Pythagorean triangle with sides a=u^2-v^2, b=2uv, c=u^2+v^2. The sequence is the area of the triangle when v=2, u=3,4,5,...at n=22A096382
• Numbers k such that 1*k + 1, 3*k + 1, 9*k + 1, 27*k + 1 are all primes.at n=26A112041
• Natural numbers that can be factored into the product of three positive integers whose minimal sum is achieved in more than one way.at n=30A112536
• Denominator of the rationals obtained from the e.g.f. D(1,x), a Debye function.at n=44A227540
• Number of (n+2)X(5+2) 0..1 arrays with each row divisible by 7 and column not divisible by 7, read as a binary number with top and left being the most significant bits.at n=1A262847
• T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with each row divisible by 7 and column not divisible by 7, read as a binary number with top and left being the most significant bits.at n=16A262849
• Number of (2+2)X(n+2) 0..1 arrays with each row divisible by 7 and column not divisible by 7, read as a binary number with top and left being the most significant bits.at n=4A262851
• Column k=3 of triangle A257673.at n=8A321948
• Sum of the positive differences of the cubed parts in each partition of n into two parts.at n=19A335639
• Those primitive elements of A337386 that have exactly one primitive nondeficient divisor (A006039).at n=11A341604
• G.f. A(x,y) satisfies: x*y*A(x,y) = Sum_{n=-oo..+oo} (-1)^n * x^(n*(n+1)/2) * A(x,y)^n, with coefficients T(n,k) of x^n*y^k in A(x,y) given as a triangle read by rows.at n=57A355360