78328

Appears in sequences

• Expansion of g.f. x*(1 +30*x +49*x^2 -71*x^3 -116*x^4)/((1+2*x)*(1-2*x^2) *(1-2*x-4*x^2)).at n=8A121960
• Number of compositions of n such that the number of parts and the greatest part are coprime.at n=17A199886
• 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=28A248904