19506

Appears in sequences

• Numbers k such that 6!*(2*k-7)!/(k!*(k-1)!) is an integer.at n=24A004786
• a(n) = floor(n*(n-1)*(n-2)*(n-3)/9).at n=22A011919
• Numbers which are the sum of their proper divisors containing the digit 5.at n=33A059464
• Numbers k such that k+1, k^2+1 and k^4+1 are primes.at n=43A070325
• McKay-Thompson series of class 36b for the Monster group.at n=45A112173