30810

Appears in sequences

• Generalized Stirling numbers, [n+3,n]_2.at n=8A001702
• a(n) = Sum_{i,j,k in Z and i^2 + j^2 + k^2 <= n} i^2 + j^2 + k^2.at n=42A014203
• Numbers n such that the denominator of the 2n-th Bernoulli number is divisible by n but sum_{d|n} sigma(d)/phi(d) is not an integer.at n=18A099008
• Numbers n such that n divides the denominator of 2n-th Bernoulli number.at n=42A106741
• McKay-Thompson series of class 16a for the Monster group.at n=19A112150
• Difference A063990(2n)-A063990(2n-1) between amicable numbers.at n=25A178542
• Smallest number k such that P = k*prime(n+1)*(prime(n)-1)+1, Q = k*prime(n+1)*P+1, R = (prime(n)-1)*Q+1 and P, Q, and R are all prime numbers.at n=39A245016
• T(n,k) is the k-th integer j > 1 such that the sum of digits of n^j is a power of n (or -1 if no such k-th integer exists); table read by downward antidiagonals.at n=51A358667