78324

Appears in sequences

• Consider a decimal number of k>=2 digits z = d_(k)*10^(k-1) + d_(k-1)*10^(k-2) + ... + d_(2)*10 + d_(1) and the sum y = Sum_{x=2..k} {Sum_{j=1..k-x}{d_(j+x-1)*10^(j-1)} - Sum_{j=1..x-1}{d_(j)*10^(j-1)}}. Sequence lists the numbers for which y = tau(z), where tau(z) is the number of divisors of z.at n=27A248904
• Triangular array T(n,k), read by rows: coefficients of strong divisibility sequence of polynomials p(1,x) = 1, p(2,x) = 1 + 4*x, p(n,x) = u*p(n-1,x) + v*p(n-2,x) for n >= 3, where u = p(2,x), v = 1 - x - x^2.at n=49A367209